Optical system

Abstract

The present application provides an optical system, which includes, in sequence from the object side to the image side along the optical axis: a first lens group with positive focal power, including: a first lens, a second lens and a third lens, wherein the first lens has positive focal power; the second lens has negative focal power; the third lens has positive focal power; a second lens group with negative focal power, including: a fourth lens, a fifth lens and a sixth lens, wherein the fourth lens has negative focal power; the fifth lens has positive focal power, and its object-side surface is convex; the sixth lens has negative focal power; wherein, when the object distance changes, the optical system is switched between a first mode and a second mode by adjusting the spacing between the second lens group and the first lens group on the optical axis, and the focal length fA of the optical system in the first mode, the focal length fB of the optical system in the second mode, the entrance pupil diameter EPDA of the optical system in the first mode and the entrance pupil diameter EPDB of the optical system in the second mode satisfy: 6.9<(fA‑fB) / (EPDA‑EPDB)<13.6.

Description

Technical Field

[0001] The present application relates to the field of optical elements, and more particularly, to an optical system. Background Art

[0002] With the rapid development of smart phones, users have higher and higher requirements for mobile phone images, and the application scenarios of mobile phone lenses are also increasing. However, considering the limited size of mobile phones, it is difficult for general mobile phone lenses to meet the needs of both long-range and close-up shooting at the same time.

[0003] The main application scenarios of periscope telephoto lenses currently on the market are limited to infinite distance shooting. The application scenarios and application times of this shooting function are very limited. At the same time, users' demand for macro shooting is increasing day by day. Therefore, it is necessary to explore a lens that can take into account both infinite distance and macro to meet user needs. Summary of the Invention

[0004] The present application provides an optical system, which includes, in order from the object side to the image side along the optical axis: a first lens group with positive focal power, including: a first lens, a second lens, and a third lens, wherein the first lens has positive focal power, and its object-side surface is convex; the second lens has negative focal power, its object-side surface is convex, and its image-side surface is concave; the third lens has positive focal power, its object-side surface is convex, and its image-side surface is convex; a second lens group with negative focal power, including: a fourth lens, a fifth lens, and a sixth lens, wherein the fourth lens has negative focal power; the third lens has positive focal power, its object-side surface is convex, and its image-side surface is convex; The fifth lens has positive focal power and its object-side surface is convex; the sixth lens has negative focal power; wherein, when the object distance changes, the optical system is switched between the first mode and the second mode by adjusting the spacing between the second lens group and the first lens group on the optical axis, and the focal length fA of the optical system in the first mode, the focal length fB of the optical system in the second mode, the entrance pupil diameter EPDA of the optical system in the first mode, and the entrance pupil diameter EPDB of the optical system in the second mode satisfy: 6.9<(fA-fB) / (EPDA-EPDB)<13.6.

[0005] In one embodiment, the optical system satisfies: 4.0<ΔT / (EPDA-EPDB)<8.2, wherein ΔT is the change in the spacing distance between the first lens group and the second lens group when the optical system switches from the first mode to the second mode, EPDA is the entrance pupil diameter of the optical system in the first mode, and EPDB is the entrance pupil diameter of the optical system in the second mode.

[0006] In one embodiment, the optical system satisfies: 1.2<(FG1-FG2) / (f3-f4)<1.7, where FG1 is the effective focal length of the first lens group, FG2 is the effective focal length of the second lens group, f3 is the effective focal length of the third lens, and f4 is the effective focal length of the fourth lens.

[0007] In one embodiment, the optical system satisfies: -1.5 < f2 / (R3 + R4) < -0.4, where f2 is the effective focal length of the second lens, R3 is the radius of curvature of the object side surface of the second lens, and R4 is the radius of curvature of the image side surface of the second lens.

[0008] In one embodiment, the optical system satisfies: 1.1 < TAN(FOVA) / TAN(FOVB) < 1.4, where FOVA is the maximum field angle of view of the optical system in the first mode, and FOVB is the maximum field angle of view of the optical system in the second mode.

[0009] In one embodiment, the optical system satisfies: 1.3 < FG1 / (CT1 + CT2 + CT3) < 1.8, where FG1 is the effective focal length of the first lens group, CT1 is the central thickness of the first lens on the optical axis, CT2 is the central thickness of the second lens on the optical axis, and CT3 is the central thickness of the third lens on the optical axis.

[0010] In one embodiment, the optical system satisfies: 1.4 < ∑CT / (fA - fB) < 1.7, where ∑CT is the sum of the central thicknesses of each lens from the first lens to the sixth lens on the optical axis, fA is the focal length of the optical system in the first mode, and fB is the focal length of the optical system in the second mode.

[0011] In one embodiment, the optical system satisfies: 1.4 < (T12 + T23) / (T45 + T56) < 2.6, where T12 is the air gap between the first lens and the second lens on the optical axis, T23 is the air gap between the second lens and the third lens on the optical axis, T45 is the air gap between the fourth lens and the fifth lens on the optical axis, and T56 is the air gap between the fifth lens and the sixth lens on the optical axis.

[0012] In one embodiment, the optical system satisfies: 0.8 < (R1 + R9) / (R5 - R6) < 1.2, where R1 is the radius of curvature of the object side surface of the first lens, R9 is the radius of curvature of the object side surface of the fifth lens, R5 is the radius of curvature of the object side surface of the third lens, and R6 is the radius of curvature of the image side surface of the third lens.

[0013] In one embodiment, the optical system satisfies: -1.3 < (fA / fB) × (f5 / f6) < -0.2, where fA is the focal length of the optical system in the first mode, fB is the focal length of the optical system in the second mode, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens.

[0014] In one embodiment, the optical system satisfies: -7.5 < FG2 / (CT5 + CT6) < -5.2, where FG2 is the effective focal length of the second lens group, CT5 is the central thickness of the fifth lens on the optical axis, and CT6 is the central thickness of the sixth lens on the optical axis.

[0015] In one embodiment, the optical system satisfies: 2.3 < ∑CT / ΔT < 2.8, where ∑CT is the sum of the central thicknesses of each lens from the first lens to the sixth lens on the optical axis, and △T is the change in the spacing distance between the first lens group and the second lens group when the optical system switches from the first mode to the second mode.

[0016] In one embodiment, the optical system satisfies: 5.6 mm < (fA / fB) × ImgH < 6.1 mm, where fA is the focal length of the optical system in the first mode, fB is the focal length of the optical system in the second mode, and ImgH is half of the diagonal length of the effective pixel area on the imaging surface of the optical system.

[0017] In one embodiment, the first lens to the sixth lens are all edged lenses.

[0018] In this application, by adjusting the spacing distance between the second lens group and the first lens group on the optical axis, the optical system can switch between the first mode and the second mode, thereby achieving mobile focusing and mobile focusing adjustment. On the one hand, by reasonably allocating the focal lengths and the entrance pupil diameters of the optical system in the first mode and the second mode, the light transmission amounts and the balance of aberrations in the first mode and the second mode can be ensured at different object distances, improving the focusing problem and enhancing the imaging quality. On the other hand, by reasonably allocating the optical powers and surface shapes of each lens, the stability of the surface shape during the molding of each lens is ensured, and the astigmatism amount is controlled within 0.3 u, which is beneficial to placing a retaining ring on the image side of the last lens, enabling the optical system to have accurate focusing while increasing the lens pushing force, ensuring reliability and stability, and stabilizing the performance of the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In conjunction with the accompanying drawings, through the following detailed description of non-limiting embodiments, other features, objects, and advantages of this application will become more apparent. In the drawings:

[0020] Figure 1 Shows a schematic structural diagram of the optical system according to Embodiment 1 of this application in the first mode;

[0021] Figures 2A to 2C Shows the axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 1 in the first mode;

[0022] Figure 31 shows a schematic structural diagram of the optical system in the second mode according to Example 1 of the present application;

[0023] Figures 4A to 4C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Example 1 in the second mode are shown;

[0024] Figure 5 1 shows a schematic structural diagram of an optical system in a first mode according to embodiment 2 of the present application;

[0025] Figures 6A to 6C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Example 2 in the first mode are shown;

[0026] Figure 7 1 shows a schematic structural diagram of the optical system in the second mode according to Example 2 of the present application;

[0027] Figures 8A to 8C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Example 2 in the second mode are shown;

[0028] Figure 9 1 shows a schematic structural diagram of an optical system in a first mode according to Example 3 of the present application;

[0029] 10A to 10C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Example 3 in the first mode are shown;

[0030] Figure 11 1 shows a schematic structural diagram of the optical system in the second mode according to Example 3 of the present application;

[0031] 12A to 12C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Example 3 in the second mode are shown;

[0032] Figure 13 1 shows a schematic structural diagram of an optical system in a first mode according to Example 4 of the present application;

[0033] 14A to 14C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Example 4 in the first mode are shown;

[0034] Figure 15 1 shows a schematic structural diagram of an optical system in a second mode according to Example 4 of the present application;

[0035] 16A to 16C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Example 4 in the second mode are shown;

[0036] Figure 171 shows a schematic structural diagram of an optical system in a first mode according to Embodiment 5 of the present application;

[0037] 18A to 18C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Example 5 in the first mode are shown;

[0038] Figure 19 1 shows a schematic structural diagram of an optical system in a second mode according to Embodiment 5 of the present application;

[0039] 20A to 20C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Example 5 in the second mode are shown;

[0040] Figure 21A and Figure 21B 3D schematic diagram and 2D schematic diagram of the optical system before trimming according to the present application are respectively shown;

[0041] Figure 21C and Figure 21D 3D schematic diagram and 2D schematic diagram of the optical system after trimming according to the present application are respectively shown. DETAILED DESCRIPTION

[0042] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of exemplary embodiments of the present application and are not intended to limit the scope of the present 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.

[0043] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of this application.

[0044] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0045] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0046] It should also be understood that the terms "comprises," "including," "having," "includes," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application." And, the term "exemplary" is intended to refer to an example or illustration.

[0047] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0048] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] The features, principles and other aspects of the present application are described in detail below.

[0050] An optical system according to an exemplary embodiment of the present application may include at least two lens groups (e.g., a first lens group and a second lens group), each lens group including at least one lens having optical power. In some examples, the first lens group includes a first lens, a second lens, and a third lens, each having optical power, and the second lens group includes a fourth lens, a fifth lens, and a sixth lens, each having optical power. The six lenses are arranged sequentially along the optical axis from the object side to the image side. Among the first through sixth lenses, any two adjacent lenses may have an air space between them.

[0051] In an exemplary embodiment, the optical system may further include at least one aperture. The aperture may be positioned at an appropriate location as needed to control the amount of light entering the optical system, for example, between the object side of the optical system and the first lens, or more specifically, between the second lens and the third lens.

[0052] In an exemplary embodiment, the first lens group may have positive optical power, and the second lens group may have negative optical power. By properly allocating the optical power of each lens group, the imaging effect can be effectively improved.

[0053] In an exemplary embodiment, the first lens has positive power and a convex object-side surface; the second lens has negative power, a convex object-side surface, and a concave image-side surface; the third lens has positive power, a convex object-side surface, and a convex image-side surface; the fourth lens has negative power; the fifth lens has positive power and a convex object-side surface; and the sixth lens has negative power. By rationally allocating the power and surface shape of the lenses included in each lens group, the surface stability of each lens during molding is ensured, and the Yass value is controlled to within 0.3u. This facilitates the placement of a pressure ring on the image-side surface of the sixth lens, ensuring that the optical system maintains precise focus while increasing the lens release force, ensuring reliability, stability, and stabilized optical system performance.

[0054] In an exemplary embodiment, when the object distance changes, the optical system switches between a first mode and a second mode by adjusting the distance between the first lens group and the second lens group on the optical axis. For example, the first mode is, for example, a telephoto position, and the second mode is, for example, a macro position. When the distance of the object from the optical system moves from the telephoto position to the macro position, focusing can be achieved by adjusting the distance between the first lens group and the second lens group on the optical axis. The focal length fA of the optical system in the first mode, the focal length fB of the optical system in the second mode, the entrance pupil diameter EPDA of the optical system in the first mode, and the entrance pupil diameter EPDB of the optical system in the second mode satisfy the following relationship: 6.9 < (fA - fB) / (EPDA - EPDB) < 13.6. By switching between the first and second modes and by properly allocating the focal lengths of the first and second modes and the entrance pupil diameters of the optical system, the balance of light flux and aberrations between the first and second modes can be maintained at different object distances, thereby improving focusing and enhancing imaging quality.

[0055] In an exemplary embodiment, the optical system satisfies: 4.0 < △T / (EPDA - EPDB) < 8.2, where △T is the change in the spacing distance between the first lens group and the second lens group when the optical system switches from the first mode to the second mode, EPDA is the entrance pupil diameter of the optical system in the first mode, and EPDB is the entrance pupil diameter of the optical system in the second mode. Controlling the relationship between the difference in the spacing between the first lens group and the second lens group on the optical axis and the entrance pupil diameter when the optical system is in the first mode and the second mode can ensure that there is no interference with the module or other mechanical components when the lens is focused and can ensure the light transmission amount of the lens.

[0056] In an exemplary embodiment, the optical system satisfies: 1.2 < (FG1 - FG2) / (f3 - f4) < 1.7, where FG1 is the effective focal length of the first lens group, FG2 is the effective focal length of the second lens group, f3 is the effective focal length of the third lens, and f4 is the effective focal length of the fourth lens. By reasonably controlling this conditional expression, the aberration of the optical system can be reduced and the performance of infinity focus and macro focus can be balanced.

[0057] In an exemplary embodiment, the optical system satisfies: -1.5 < f2 / (R3 + R4) < -0.4, where f2 is the effective focal length of the second lens, R3 is the curvature radius of the object side surface of the second lens, and R4 is the curvature radius of the image side surface of the second lens. By controlling this conditional expression, the overall shape of the second lens can be controlled, the surface shape stability during lens processing can be ensured, and the performance of infinity focus and macro focus can be balanced.

[0058] In an exemplary embodiment, the optical system satisfies: 1.1 < TAN(FOVA) / TAN(FOVB) < 1.4, where FOVA is the maximum field angle of the optical system in the first mode and FOVB is the maximum field angle of the optical system in the second mode. By controlling the maximum field angle of the optical system in the first mode and the maximum field angle of the optical system in the second mode, the ratio of image height to focal length can be effectively controlled and the system aberration stability can be ensured.

[0059] In an exemplary embodiment, the optical system satisfies: 1.3 < FG1 / (CT1 + CT2 + CT3) < 1.8, where FG1 is the effective focal length of the first lens group, CT1 is the central thickness of the first lens on the optical axis, CT2 is the central thickness of the second lens on the optical axis, and CT3 is the central thickness of the third lens on the optical axis. By reasonably controlling this conditional expression, it is beneficial to meet the processing requirements, reduce the system aberration, reduce the temperature drift change amount, and ensure the performance stability.

[0060] In an exemplary embodiment, the optical system satisfies: 1.4 < ∑CT / (fA - fB) < 1.7, where ∑CT is the sum of the central thicknesses of each lens from the first lens to the sixth lens on the optical axis, fA is the focal length of the optical system in the first mode, and fB is the focal length of the optical system in the second mode. By controlling this conditional expression, it is beneficial to balance the performance of telephoto and close-up shooting while reducing the variation of temperature drift.

[0061] In an exemplary embodiment, the optical system satisfies: 1.4 < (T12 + T23) / (T45 + T56) < 2.6, where T_{12} is the air gap between the first lens and the second lens on the optical axis, T_{23} is the air gap between the second lens and the third lens on the optical axis, T_{45} is the air gap between the fourth lens and the fifth lens on the optical axis, and T_{56} is the air gap between the fifth lens and the sixth lens on the optical axis. By reasonably controlling this conditional expression, it is beneficial to meet the assembly tolerance and ensure the assembly stability.

[0062] In an exemplary embodiment, the optical system satisfies: 0.8 < (R1 + R9) / (R5 - R6) < 1.2, where R1 is the radius of curvature of the object side of the first lens, R9 is the radius of curvature of the object side of the fifth lens, R5 is the radius of curvature of the object side of the third lens, and R6 is the radius of curvature of the image side of the third lens. By reasonably controlling this conditional expression, the energy level of the "one-word ghost image" can be controlled, while ensuring the assembly space of the retaining ring, ensuring that the fifth lens does not cut into the effective diameter, and meeting the stability of the die process.

[0063] In an exemplary embodiment, the optical system satisfies: -1.3 < (fA / fB)×(f5 / f6) < -0.2, where fA is the focal length of the optical system in the first mode, fB is the focal length of the optical system in the second mode, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens. By reasonably controlling this conditional expression, the system error can be effectively reduced while reducing the variation of temperature drift of the optical system.

[0064] In an exemplary embodiment, the optical system satisfies: -7.5 < FG2 / (CT5 + CT6) < -5.2, where FG2 is the effective focal length of the second lens group, CT5 is the central thickness of the fifth lens on the optical axis, and CT6 is the central thickness of the sixth lens on the optical axis. By reasonably controlling this conditional expression, it is beneficial to reasonably distribute the optical power, while balancing the optical performance of infinity focus and macro focus, and is beneficial to ensuring the processing stability of the lens.

[0065] In an exemplary embodiment, the optical system satisfies the following condition: 2.3 < ∑CT / ΔT < 2.8, where ∑CT is the sum of the center thicknesses of each of the first through sixth lenses along the optical axis, and ΔT is the change in the separation between the first and second lens groups when the optical system switches from the first mode to the second mode. By properly controlling this condition, it is possible to ensure that the lens does not interfere with the module or other mechanical components when switching between telephoto and macro focus.

[0066] In an exemplary embodiment, the optical system satisfies the following: 5.6 mm < (fA / fB) × ImgH < 6.1 mm, where fA is the focal length of the optical system in the first mode, fB is the focal length of the optical system in the second mode, and ImgH is half the diagonal length of the effective pixel area on the imaging plane of the optical system. By properly controlling this conditional expression, the distortion and field of view of the optical system can be effectively controlled, aberrations can be reduced, and the amount of temperature drift of the optical system can be minimized.

[0067] In an exemplary embodiment, the first through sixth lenses are all edged lenses. For example, the edged lenses are not fully circular. Another example is that the lenses have opposite sides edged to resemble a racetrack shape. More specifically, the first through sixth lenses may be edged on opposite sides, or only on one side. However, the present application is not limited to the aforementioned edge cutting methods; other edge cutting methods may be designed based on actual needs, if necessary. 21A to 21D : shows a comparison diagram of the optical system before and after cutting according to an exemplary embodiment of the present application, wherein: Figure 21A It shows the 3D schematic diagram of the optical system without cutting edges. Figure 21B It shows the 2D schematic diagram of the optical system without cutting edges. Figure 21C The 3D schematic diagram of the optical system after trimming is shown. Figure 21D Figure 2 shows a 2D schematic diagram of the optical system after trimming. Figure 21C and Figure 21D As can be seen, the first through sixth lenses of the optical system have been trimmed on opposite sides, significantly reducing the lens height. Understandably, for optical systems with excessively large apertures and overall lens diameters, trimming the first through sixth lenses can reduce the overall height of the lens when laid flat, saving space in the phone while minimizing the impact on aperture size and performance.

[0068] In an exemplary embodiment, the optical system may further include a filter for correcting color deviation and / or a protective glass for protecting a photosensitive element located on the imaging surface.

[0069] The optical system of the present application adjusts the spacing between the first lens group and the second lens group on the optical axis through the combination of two groups, so that the optical system switches between the first mode and the second mode, thereby realizing mobile focus and mobile focus adjustment. For example, the present application can realize the shooting requirements from infinity to macro 5cm, meeting the demand for larger magnification under macro. At the same time, in order to meet the shooting requirements in dark environments, the present application can adopt a large aperture design. Considering the overall height limit of the mobile phone, a full-edge cutting solution of the lens can be adopted, that is, the opposite sides of the first lens to the sixth lens are cut to meet the mechanical size requirements. The optical system of the present application takes into account the performance of infinity and macro through the adjustment of the lens surface shape, the matching of materials and the function of mobile focus, realizing the diversity of periscope lens functions.

[0070] In addition, the present application, on one hand, can reasonably allocate the focal lengths of the first and second modes and the entrance pupil diameter of the optical system, thereby maintaining a balance between the light throughput and aberrations of the first and second modes at different object distances, thereby improving focusing and enhancing image quality. On the other hand, by reasonably allocating the focal power, surface shape, center thickness of each lens, and distance between each lens on the optical axis of each lens group, the above-mentioned optical system can achieve at least one of the following beneficial effects while ensuring precise focusing: balancing the aberrations generated by the front and rear lens groups; and achieving miniaturization.

[0071] In an embodiment of the present application, at least one of the mirror surfaces of each lens group is an aspherical mirror surface, that is, at least one of the object side surface of the first lens to the image side surface of the sixth lens is an aspherical mirror surface. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After adopting an aspherical lens, the aberration that occurs during imaging can be eliminated as much as possible, thereby improving the imaging quality. Optionally, at least one of the object side surface and image side surface of the first lens, the second lens and the third lens included in the first lens group and the fourth lens, the fifth lens and the sixth lens included in the second lens group is an aspherical mirror surface. Optionally, the object side surface and image side surface of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all aspherical mirror surfaces.

[0072] Those skilled in the art will appreciate that the number of lenses comprising the optical system can be varied to achieve the various results and advantages described herein without departing from the claimed technical solutions. For example, while the embodiments describe two lens groups, each including three lenses, as an example, the optical system is not limited to including two lens groups, and each lens group is not limited to including three lenses. If desired, the optical system may also include other numbers of lens groups, and each lens group may also include other numbers of lenses.

[0073] Specific embodiments of the optical system applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0074] Example 1

[0075] The following reference Figures 1 to 4C An optical system according to Example 1 of the present application is described. Figure 1 and Figure 3 Schematic diagrams of the structures of the optical system in the first mode and the second mode according to Example 1 of the present application are respectively shown.

[0076] like Figure 1 and Figure 3 As shown, the optical system comprises, from the object side to the image side along the optical axis, a first lens group G1 and a second lens group G2. The first lens group G1 has positive refractive power, while the second lens group G2 has negative refractive power. The first lens group G1 comprises, in order, a first lens E1, a second lens E2, and a third lens E3. The second lens group G2 comprises, in order, a fourth lens E4, a fifth lens E5, and a sixth lens E6. The optical system also includes an aperture stop STO, a filter E7, and an imaging surface S15.

[0077] The first lens E1 has positive focal power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has negative focal power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive focal power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative focal power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has positive focal power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has negative focal power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the subject passes through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0078] Table 1 shows the basic parameters of the optical system of Example 1, wherein the units of curvature radius, thickness / distance and focal length are all millimeters (mm).

[0079]

[0080] Table 1

[0081] In this embodiment, half the diagonal length ImgH of the effective pixel area on the imaging surface S15 is 3.90 mm, the sum ΣCT of the center thicknesses of the first to sixth lenses on the optical axis is 8.02 mm, the effective focal length FG1 of the first lens group is 8.88 mm, and the effective focal length FG2 of the second lens group is -10.56 mm.

[0082] Referring to Table 1, in the first mode, the distance OBJ from the object to the object-side surface of the first lens on the optical axis is infinity, that is, the object distance is infinity, the distance between the third lens of the first lens group G1 and the fourth lens of the second lens group G2 on the optical axis is 0.9595 mm, the distance between the sixth lens of the second lens group G2 and the filter E7 on the optical axis is 3.5928 mm, the focal length fA of the optical system in the first mode is 15.17 mm, the maximum field of view FOVA of the optical system in the first mode is 28.80°, and the entrance pupil diameter EPDA of the optical system in the first mode is 7.99 mm. In the second mode, the optical axis distance OBJ from the subject to the object-side surface of the first lens is 49.3740mm, the optical axis distance between the third lens element of the first lens group G1 and the fourth lens element of the second lens group G2 is 3.9595mm, and the optical axis distance between the sixth lens element of the second lens group G2 and filter E7 is 0.5928mm. The focal length fB of the optical system in the second mode is 10.21mm, the maximum field of view FOVB of the optical system in the second mode is 25.88°, and the entrance pupil diameter EPDB of the optical system in the second mode is 7.41mm. During zooming, the optical axis distance between adjacent lenses in the first lens group G1 remains unchanged, and the optical axis distance between adjacent lenses in the second lens group G2 remains unchanged. When the optical system switches from the first mode to the second mode, the change in the separation distance ΔT between the first lens group G1 and the second lens group G2 is 3.00mm.

[0083] In this embodiment, the surface shape x of the aspheric surface included in the object-side surface and the image-side surface of the first lens E1 to the sixth lens E6 can be defined by, but not limited to, the following aspheric surface formula:

[0084]

[0085] Wherein, x is the distance vector height of the aspheric surface from the vertex of the aspheric surface at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the conic coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Tables 2 and 3 below show the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, 10 、A 12 、A 14 、A 16 、A 18 、A 20 、A 22 、A 24 、A 26 、A 28 and A 30 .

[0086] Face number A4 A6 A8 A10 A12 A14 A16 S1 2.1463E-04 3.5522E-06 -1.0286E-05 -1.7405E-06 7.0010E-07 2.6097E-07 -1.7658E-07 S2 3.6233E-03 7.0866E-05 -7.4320E-04 4.0637E-04 -1.2312E-04 2.4148E-05 -3.2188E-06 S3 -1.5150E-03 3.2351E-04 -1.6990E-03 1.0478E-03 -3.5336E-04 7.7072E-05 -1.1376E-05 S4 -5.3092E-03 8.6256E-04 -4.3202E-03 3.5381E-03 -1.6142E-03 4.9095E-04 -1.0546E-04 S5 -1.5220E-03 4.4754E-04 -1.8885E-03 1.2535E-03 -4.5070E-04 9.9871E-05 -1.2475E-05 S6 -4.9811E-04 2.0698E-03 -3.1536E-03 2.7408E-03 -1.5721E-03 6.3119E-04 -1.8162E-04 S7 6.4454E-02 -1.1217E-02 -9.1803E-03 1.7752E-02 -1.6256E-02 9.7391E-03 -4.0745E-03 S8 4.4394E-02 -2.4238E-02 6.0555E-02 -1.0718E-01 1.2725E-01 -1.0532E-01 6.2109E-02 S9 -3.4381E-02 2.0887E-03 8.3332E-03 -6.2405E-03 1.6377E-03 3.5393E-04 -4.2401E-04 S10 -2.9565E-02 -3.3349E-03 8.2561E-03 6.9792E-04 -8.0957E-03 7.8327E-03 -4.1551E-03 S11 -7.7621E-03 3.9876E-03 -2.7892E-02 5.4609E-02 -5.8983E-02 4.1127E-02 -1.9740E-02 S12 9.8387E-04 -1.3514E-02 1.7067E-02 -1.4617E-02 8.8967E-03 -3.9725E-03 1.3188E-03

[0087] Table 2

[0088] Face number A18 A20 A22 A24 A26 A28 A30 S1 4.3296E-08 -6.1147E-09 5.4975E-10 -3.2097E-11 1.1830E-12 -2.5073E-14 2.3332E-16 S2 2.9505E-07 -1.8334E-08 7.3811E-10 -1.7367E-11 1.8124E-13 0.0000E+00 0.0000E+00 S3 1.1281E-06 -6.9800E-08 1.9262E-09 6.1297E-11 -7.4911E-12 2.6167E-13 -3.4026E-15 S4 1.6317E-05 -1.8193E-06 1.4419E-07 -7.8862E-09 2.8164E-10 -5.8861E-12 5.4408E-14 S5 2.5045E-07 2.0943E-07 -4.1165E-08 4.0426E-09 -2.3109E-10 7.3243E-12 -9.9911E-14 S6 3.7824E-05 -5.7000E-06 6.1464E-07 -4.6186E-08 2.2951E-09 -6.7744E-11 8.9874E-13 S7 1.2197E-03 -2.6297E-04 4.0523E-05 -4.3549E-06 3.1010E-07 -1.3150E-08 2.5137E-10 S8 -2.6389E-02 8.0918E-03 -1.7735E-03 2.7088E-04 -2.7384E-05 1.6467E-06 -4.4597E-08 S9 1.5173E-04 -2.9127E-05 3.0023E-06 -1.1444E-07 -5.4107E-09 4.7519E-10 0.0000E+00 S10 1.4221E-03 -3.2728E-04 5.0485E-05 -5.0139E-06 2.8994E-07 -7.4186E-09 0.0000E+00 S11 6.7135E-03 -1.6326E-03 2.8199E-04 -3.3759E-05 2.6607E-06 -1.2403E-07 2.5879E-09 S12 -3.2563E-04 5.9276E-05 -7.8114E-06 7.2202E-07 -4.4263E-08 1.6126E-09 -2.6380E-11

[0089] Table 3

[0090] Figure 2A and Figure 4A The axial chromatic aberration curves of the optical system of Example 1 in the first mode and the second mode are respectively shown, which indicate the deviation of the convergent focus of light of different wavelengths after passing through the lens. Figure 2B and Figure 4B Astigmatism curves of the optical system of Example 1 in the first mode and the second mode are shown, respectively, which represent meridional field curvature and sagittal field curvature. Figure 2C and Figure 4C The distortion curves of the optical system of Example 1 in the first mode and the second mode are shown respectively, which represent the distortion values ​​corresponding to different field angles. Figures 2A to 2C 、 Figures 4A to 4C It can be seen that the optical system provided in Example 1 can focus accurately, thereby achieving good imaging quality.

[0091] Example 2

[0092] The following reference Figures 5 to 8C The optical system according to Example 2 of the present application is described. In this embodiment and the following embodiments, some descriptions similar to those in Example 1 will be omitted for the sake of brevity. Figure 5 and Figure 7 Schematic diagrams of the structures of the optical system in the first mode and the second mode according to Example 2 of the present application are respectively shown.

[0093] like Figure 5 and Figure 7 As shown, the optical system comprises, from the object side to the image side along the optical axis, a first lens group G1 and a second lens group G2. The first lens group G1 has positive refractive power, while the second lens group G2 has negative refractive power. The first lens group G1 comprises, in order, a first lens E1, a second lens E2, and a third lens E3. The second lens group G2 comprises, in order, a fourth lens E4, a fifth lens E5, and a sixth lens E6. The optical system also includes an aperture stop STO, a filter E7, and an imaging surface S15.

[0094] The first lens E1 has positive focal power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has negative focal power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive focal power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative focal power, with its object-side surface S7 being concave and its image-side surface S8 being concave. The fifth lens E5 has positive focal power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has negative focal power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the subject passes through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0095] Table 4 shows the basic parameters of the optical system of Example 2, where the units of curvature radius, thickness / distance, and focal length are all in millimeters (mm). Tables 5 and 6 show the high-order coefficients of each aspheric mirror surface that can be used in Example 2, where the surface shape of each aspheric surface can be defined by formula (1) given in Example 1 above.

[0096]

[0097] Table 4

[0098] In this embodiment, half the diagonal length ImgH of the effective pixel area on the imaging surface S15 is 3.90 mm, the sum ΣCT of the center thicknesses of the first to sixth lenses on the optical axis is 7.41 mm, the effective focal length FG1 of the first lens group is 8.84 mm, and the effective focal length FG2 of the second lens group is -10.62 mm.

[0099] Referring to Table 4, in the first mode, the distance OBJ from the object to the object-side surface of the first lens on the optical axis is infinity, that is, the object distance is infinity, the distance between the third lens of the first lens group G1 and the fourth lens of the second lens group G2 on the optical axis is 0.9195 mm, the distance between the sixth lens of the second lens group G2 and the filter E7 on the optical axis is 4.8680 mm, the focal length fA of the optical system in the first mode is 15.21 mm, the maximum field of view FOVA of the optical system in the first mode is 28.60°, and the entrance pupil diameter EPDA of the optical system in the first mode is 7.45 mm. In the second mode, the optical axis distance OBJ from the subject to the object-side surface of the first lens is 48.2520mm, the optical axis distance between the third lens element of the first lens group G1 and the fourth lens element of the second lens group G2 is 3.9195mm, and the optical axis distance between the sixth lens element of the second lens group G2 and the filter E7 is 1.8680mm. The focal length fB of the optical system in the second mode is 10.23mm, the maximum field of view FOVB of the optical system in the second mode is 22.60°, and the entrance pupil diameter EPDB of the optical system in the second mode is 7.08mm. During zooming, the optical axis distance between adjacent lenses in the first lens group G1 remains unchanged, and the optical axis distance between adjacent lenses in the second lens group G2 remains unchanged. When the optical system switches from the first mode to the second mode, the change in the separation distance ΔT between the first lens group G1 and the second lens group G2 is 3.00mm.

[0100] Face number A4 A6 A8 A10 A12 A14 A16 S1 -4.9349E-04 -1.0337E-04 1.0509E-04 -5.5519E-05 1.9077E-05 -4.5149E-06 7.5545E-07 S2 -9.9782E-03 3.7367E-03 -1.0334E-03 2.4310E-04 -4.7315E-05 7.2845E-06 -8.5976E-07 S3 -5.2709E-02 1.5254E-02 -1.5688E-03 -6.4840E-04 3.5648E-04 -8.5276E-05 1.0416E-05 S4 -6.6252E-02 2.5231E-02 -7.9926E-03 2.4878E-03 -8.0833E-04 2.4892E-04 -6.4087E-05 S5 -1.2740E-02 1.3822E-03 3.5627E-04 -1.0763E-04 -2.7087E-05 2.5443E-05 -8.6556E-06 S6 5.1126E-04 -1.4600E-03 2.0136E-03 -1.6988E-03 1.0235E-03 -4.4488E-04 1.4083E-04 S7 -1.2710E-02 2.8183E-02 -2.2105E-02 1.4910E-02 -8.8554E-03 4.2098E-03 -1.4942E-03 S8 -4.0762E-02 3.7452E-02 -1.6997E-02 1.8593E-03 4.9549E-03 -5.1253E-03 2.7815E-03 S9 -3.8639E-02 8.8086E-03 -8.5449E-03 1.2589E-02 -1.1660E-02 7.1200E-03 -3.0352E-03 S10 -1.8662E-02 -1.6512E-02 7.8775E-03 6.3574E-03 -9.5033E-03 5.9935E-03 -2.4120E-03 S11 1.0877E-02 -4.1575E-02 2.1183E-02 2.6277E-03 -9.2614E-03 6.1287E-03 -2.4194E-03 S12 1.0235E-02 -2.9533E-02 2.3416E-02 -1.1669E-02 4.0797E-03 -1.0311E-03 1.7255E-04

[0101] Table 5

[0102] Face number A18 A20 A22 A24 A26 A28 A30 S1 -9.0225E-08 7.6500E-09 -4.5007E-10 1.7478E-11 -4.0308E-13 4.1817E-15 0.0000E+00 S2 7.5576E-08 -4.7622E-09 2.0242E-10 -5.1824E-12 6.0244E-14 0.0000E+00 0.0000E+00 S3 -7.0784E-08 -2.0500E-07 3.7643E-08 -3.5907E-09 2.0216E-10 -6.3716E-12 8.7098E-14 S4 1.2755E-05 -1.8828E-06 2.0033E-07 -1.4856E-08 7.2666E-10 -2.1039E-11 2.7282E-13 S5 1.8373E-06 -2.6707E-07 2.7038E-08 -1.8737E-09 8.4499E-11 -2.2242E-12 2.5770E-14 S6 -3.2631E-05 5.5182E-06 -6.7216E-07 5.7329E-08 -3.2440E-09 1.0925E-10 -1.6553E-12 S7 3.8046E-04 -6.7028E-05 7.7318E-06 -5.2428E-07 1.5820E-08 0.0000E+00 0.0000E+00 S8 -9.5900E-04 2.1569E-04 -3.0714E-05 2.5174E-06 -9.0550E-08 0.0000E+00 0.0000E+00 S9 9.2550E-04 -2.0305E-04 3.1795E-05 -3.4684E-06 2.5060E-07 -1.0786E-08 2.0946E-10 S10 6.7067E-04 -1.3129E-04 1.8043E-05 -1.7082E-06 1.0659E-07 -3.9699E-09 6.7297E-11 S11 6.4647E-04 -1.1982E-04 1.5296E-05 -1.3088E-06 7.1040E-08 -2.1857E-09 2.8556E-11 S12 -1.1503E-05 -2.4722E-06 8.1896E-07 -1.1227E-07 8.6152E-09 -3.6043E-10 6.4248E-12

[0103] Table 6

[0104] Figure 6A and Figure 8A The axial chromatic aberration curves of the optical system of Example 2 in the first mode and the second mode are respectively shown, which indicate the deviation of the convergent focus of light of different wavelengths after passing through the lens. Figure 2B and Figure 8B Astigmatism curves of the optical system of Example 2 in the first mode and the second mode are shown, respectively, which represent meridional field curvature and sagittal field curvature. Figure 6C and Figure 8C The distortion curves of the optical system of Example 2 in the first mode and the second mode are shown respectively, which represent the distortion values ​​corresponding to different field angles. Figures 6A to 6C 、 Figures 8A to 8C It can be seen that the optical system provided in Example 2 can focus accurately, thereby achieving good imaging quality.

[0105] Example 3

[0106] The following reference Figures 9 to 12C An optical system according to Example 3 of the present application is described. Figure 9 and Figure 11 Schematic diagrams of the structures of the optical system in the first mode and the second mode according to Example 3 of the present application are respectively shown.

[0107] like Figure 9 and Figure 11 As shown, the optical system comprises, from the object side to the image side along the optical axis, a first lens group G1 and a second lens group G2. The first lens group G1 has positive refractive power, while the second lens group G2 has negative refractive power. The first lens group G1 comprises, in order, a first lens E1, a second lens E2, and a third lens E3. The second lens group G2 comprises, in order, a fourth lens E4, a fifth lens E5, and a sixth lens E6. The optical system also includes an aperture stop STO, a filter E7, and an imaging surface S15.

[0108] The first lens E1 has positive focal power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative focal power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive focal power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative focal power, with its object-side surface S7 being concave and its image-side surface S8 being concave. The fifth lens E5 has positive focal power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative focal power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the subject passes through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0109] Table 7 shows the basic parameters of the optical system of Example 3, where the units of curvature radius, thickness / distance, and focal length are all in millimeters (mm). Tables 8 and 9 show the high-order coefficients of each aspheric mirror surface that can be used in Example 3, where the surface shape of each aspheric surface can be defined by formula (1) given in Example 1 above.

[0110]

[0111] Table 7

[0112] In this embodiment, half the diagonal length ImgH of the effective pixel area on the imaging surface S15 is 3.80 mm, the sum ΣCT of the center thicknesses of the first to sixth lenses on the optical axis is 8.07 mm, the effective focal length FG1 of the first lens group is 8.82 mm, and the effective focal length FG2 of the second lens group is -9.12 mm.

[0113] Referring to Table 7, in the first mode, the distance OBJ from the object to the object-side surface of the first lens on the optical axis is infinity, that is, the object distance is infinity, the distance between the third lens of the first lens group G1 and the fourth lens of the second lens group G2 on the optical axis is 0.8593 mm, the distance between the sixth lens of the second lens group G2 and the filter E7 on the optical axis is 4.8680 mm, the focal length fA of the optical system in the first mode is 15.31 mm, the maximum field of view FOVA of the optical system in the first mode is 27.82°, and the entrance pupil diameter EPDA of the optical system in the first mode is 7.61 mm. In the second mode, the optical axis distance OBJ from the subject to the object-side surface of the first lens is 48.0000mm, the optical axis distance between the third lens element of the first lens group G1 and the fourth lens element of the second lens group G2 is 3.8593mm, and the optical axis distance between the sixth lens element of the second lens group G2 and the filter E7 is 1.8680mm. The focal length fB of the optical system in the second mode is 9.75mm, the maximum field of view FOVB of the optical system in the second mode is 25.20°, and the entrance pupil diameter EPDB of the optical system in the second mode is 7.04mm. During zooming, the optical axis distance between adjacent lenses in the first lens group G1 remains unchanged, and the optical axis distance between adjacent lenses in the second lens group G2 remains unchanged. When the optical system switches from the first mode to the second mode, the change in the separation distance ΔT between the first lens group G1 and the second lens group G2 is 3.00mm.

[0114]

[0115]

[0116] Table 8

[0117] Face number A18 A20 A22 A24 A26 A28 A30 S1 1.3775E-08 -2.0440E-09 1.6417E-10 -7.7864E-12 2.0537E-13 -2.3302E-15 0.0000E+00 S2 -1.2662E-08 4.1650E-10 -5.4636E-12 -1.7142E-14 0.0000E+00 0.0000E+00 0.0000E+00 S3 1.2250E-06 -1.5527E-07 1.2759E-08 -6.6271E-10 1.9824E-11 -2.6071E-13 0.0000E+00 S4 4.7569E-06 -6.8813E-07 6.2311E-08 -3.3967E-09 9.4364E-11 -4.5386E-13 -2.5127E-14 S5 5.9957E-06 -8.8600E-07 8.7322E-08 -5.6795E-09 2.3210E-10 -5.3187E-12 5.0694E-14 S6 -3.6895E-05 5.9517E-06 -6.8546E-07 5.4912E-08 -2.9044E-09 9.1117E-11 -1.2833E-12 S7 5.9653E-04 -1.3759E-04 2.1476E-05 -2.1642E-06 1.2706E-07 -3.3008E-09 0.0000E+00 S8 5.5870E-04 -1.1075E-04 1.4251E-05 -1.0701E-06 3.5552E-08 0.0000E+00 0.0000E+00 S9 5.6963E-06 -2.6726E-07 -8.2901E-10 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 5.2305E-08 -6.7288E-09 3.9840E-11 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 7.3662E-03 -1.7120E-03 2.9092E-04 -3.4984E-05 2.8141E-06 -1.3565E-07 2.9599E-09 S12 1.8105E-03 -3.1915E-04 4.1215E-05 -3.7734E-06 2.3146E-07 -8.5192E-09 1.4209E-10

[0118] Table 9

[0119] Figure 10A and Figure 12A The axial chromatic aberration curves of the optical system of Example 3 in the first mode and the second mode are respectively shown, which indicate the deviation of the convergent focus of light of different wavelengths after passing through the lens. Figure 10B and Figure 12B Astigmatism curves of the optical system of Example 3 in the first mode and the second mode are shown, respectively, which represent meridional field curvature and sagittal field curvature. Figure 10C and Figure 12C The distortion curves of the optical system of Example 3 in the first mode and the second mode are shown respectively, which represent the distortion values ​​corresponding to different field angles. 10A to 10C 、 12A to 12C It can be seen that the optical system provided in Example 3 can focus accurately, thereby achieving good imaging quality.

[0120] Example 4

[0121] The following reference Figures 13 to 16C An optical system according to Example 4 of the present application is described. Figure 13 and Figure 15 Schematic diagrams of the structures of the optical system in the first mode and the second mode according to Example 4 of the present application are respectively shown.

[0122] like Figure 13 and Figure 15 As shown, the optical system comprises, from the object side to the image side along the optical axis, a first lens group G1 and a second lens group G2. The first lens group G1 has positive refractive power, while the second lens group G2 has negative refractive power. The first lens group G1 comprises, in order, a first lens E1, a second lens E2, and a third lens E3. The second lens group G2 comprises, in order, a fourth lens E4, a fifth lens E5, and a sixth lens E6. The optical system also includes an aperture stop STO, a filter E7, and an imaging surface S15.

[0123] The first lens E1 has positive focal power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative focal power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive focal power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative focal power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive focal power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has negative focal power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the subject passes through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0124] Table 10 shows the basic parameters of the optical system of Example 4, where the units of curvature radius, thickness / distance, and focal length are all in millimeters (mm). Tables 11 and 12 show the high-order coefficients of each aspherical mirror surface that can be used in Example 4, where the surface shape of each aspherical surface can be defined by formula (1) given in Example 1 above.

[0125]

[0126] Table 10

[0127] In this embodiment, half the diagonal length ImgH of the effective pixel area on the imaging surface S15 is 3.80 mm, the sum ΣCT of the center thicknesses of the first to sixth lenses on the optical axis is 7.97 mm, the effective focal length FG1 of the first lens group is 8.75 mm, and the effective focal length FG2 of the second lens group is -9.59 mm.

[0128] Referring to Table 10, in the first mode, the distance OBJ from the object to the object-side surface of the first lens on the optical axis is infinity, that is, the object distance is infinity, the distance on the optical axis between the third lens of the first lens group G1 and the fourth lens of the second lens group G2 is 0.8300 mm, the distance on the optical axis between the sixth lens of the second lens group G2 and the filter E7 is 4.9070 mm, the focal length fA of the optical system in the first mode is 14.81 mm, the maximum field of view FOVA of the optical system in the first mode is 28.74°, and the entrance pupil diameter EPDA of the optical system in the first mode is 7.75 mm. In the second mode, the optical axis distance OBJ from the subject to the object-side surface of the first lens is 48.0000mm, the optical axis distance between the third lens element of the first lens group G1 and the fourth lens element of the second lens group G2 is 3.8300mm, and the optical axis distance between the sixth lens element of the second lens group G2 and the filter E7 is 1.9070mm. The focal length fB of the optical system in the second mode is 9.68mm, the maximum field of view FOVB of the optical system in the second mode is 26.00°, and the entrance pupil diameter EPDB of the optical system in the second mode is 7.09mm. During zooming, the optical axis distance between adjacent lenses in the first lens group G1 remains unchanged, and the optical axis distance between adjacent lenses in the second lens group G2 remains unchanged. When the optical system switches from the first mode to the second mode, the change in the spacing ΔT between the first lens group G1 and the second lens group G2 is 3.00mm.

[0129]

[0130]

[0131] Table 11

[0132] Face number A18 A20 A22 A24 A26 A28 A30 S1 -1.2762E-07 9.7192E-09 -5.1227E-10 1.7752E-11 -3.6351E-13 3.3307E-15 0.0000E+00 S2 -6.1283E-09 5.5352E-11 6.9734E-12 -2.0829E-13 0.0000E+00 0.0000E+00 0.0000E+00 S3 -2.5733E-06 2.3470E-07 -1.4847E-08 6.2104E-10 -1.5464E-11 1.7362E-13 0.0000E+00 S4 4.8536E-05 -7.6809E-06 8.2422E-07 -5.9619E-08 2.7918E-09 -7.6579E-11 9.3570E-13 S5 5.9826E-05 -9.1656E-06 9.5857E-07 -6.7820E-08 3.1123E-09 -8.3746E-11 1.0042E-12 S6 1.3114E-05 -2.4200E-06 3.0132E-07 -2.5210E-08 1.3614E-09 -4.2926E-11 6.0081E-13 S7 1.2088E-05 -1.7044E-05 3.9203E-06 -4.6717E-07 2.9766E-08 -8.0402E-10 0.0000E+00 S8 -6.5898E-04 1.1593E-04 -1.3594E-05 9.5033E-07 -2.9887E-08 0.0000E+00 0.0000E+00 S9 -1.1403E-06 -2.0084E-08 -3.9160E-10 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 -8.5508E-06 2.5848E-07 1.4931E-09 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 1.9578E-02 -5.0801E-03 9.4518E-04 -1.2297E-04 1.0620E-05 -5.4688E-07 1.2706E-08 S12 -1.0096E-04 1.0281E-05 -6.6253E-07 2.1653E-08 9.0065E-11 -3.1482E-11 7.6009E-13

[0133] Table 12

[0134] Figure 14A and Figure 16A The axial chromatic aberration curves of the optical system of Example 4 in the first mode and the second mode are respectively shown, which indicate the deviation of the convergent focus of light of different wavelengths after passing through the lens. Figure 14B and Figure 16B Astigmatism curves of the optical system of Example 4 in the first mode and the second mode are shown, respectively, which represent meridional field curvature and sagittal field curvature. Figure 14C and Figure 16C The distortion curves of the optical system of Example 4 in the first mode and the second mode are shown respectively, which represent the distortion values ​​corresponding to different field angles. 14A to 16C 、 14A to 16CIt can be seen that the optical system provided in Example 4 can focus accurately, thereby achieving good imaging quality.

[0135] Example 5

[0136] The following reference Figures 17 to 20C An optical system according to Example 5 of the present application is described. Figure 17 and Figure 19 Schematic diagrams of the structures of the optical system in the first mode and the second mode according to Example 5 of the present application are respectively shown.

[0137] like Figure 17 and Figure 19 As shown, the optical system comprises, from the object side to the image side along the optical axis, a first lens group G1 and a second lens group G2. The first lens group G1 has positive refractive power, while the second lens group G2 has negative refractive power. The first lens group G1 comprises, in order, a first lens E1, a second lens E2, and a third lens E3. The second lens group G2 comprises, in order, a fourth lens E4, a fifth lens E5, and a sixth lens E6. The optical system also includes an aperture stop STO, a filter E7, and an imaging surface S15.

[0138] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being convex. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the subject passes through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0139] Table 13 shows the basic parameters of the optical system of Example 5, where the units of curvature radius, thickness / distance, and focal length are all in millimeters (mm). Tables 14 and 15 show the high-order coefficients of the various aspherical mirror surfaces that can be used in Example 5, where the surface shapes of the various aspherical surfaces can be defined by formula (1) given in Example 1 above.

[0140]

[0141]

[0142] Table 13

[0143] In this embodiment, half the diagonal length ImgH of the effective pixel area on the imaging surface S15 is 3.80 mm, the sum ΣCT of the center thicknesses of the first to sixth lenses on the optical axis is 7.39 mm, the effective focal length FG1 of the first lens group is 8.83 mm, and the effective focal length FG2 of the second lens group is -9.88 mm.

[0144] Referring to Table 13, in the first mode, the distance OBJ from the object to the object-side surface of the first lens on the optical axis is infinity, that is, the object distance is infinity, the distance between the third lens of the first lens group G1 and the fourth lens of the second lens group G2 on the optical axis is 0.8800 mm, the distance between the sixth lens of the second lens group G2 and the filter E7 on the optical axis is 3.5630 mm, the focal length fA of the optical system in the first mode is 15.17 mm, the maximum field of view FOVA of the optical system in the first mode is 28.00°, and the entrance pupil diameter EPDA of the optical system in the first mode is 7.97 mm. In the second mode, the optical axis distance OBJ from the subject to the object-side surface of the first lens is 47.7230mm, the optical axis distance between the third lens element of the first lens group G1 and the fourth lens element of the second lens group G2 is 3.8800mm, and the optical axis distance between the sixth lens element of the second lens group G2 and the filter E7 is 0.5630mm. The focal length fB of the optical system in the second mode is 9.97mm, the maximum field of view FOVB of the optical system in the second mode is 25.58°, and the entrance pupil diameter EPDB of the optical system in the second mode is 7.22mm. During zooming, the optical axis distance between adjacent lenses in the first lens group G1 remains unchanged, and the optical axis distance between adjacent lenses in the second lens group G2 remains unchanged. When the optical system switches from the first mode to the second mode, the change in the spacing ΔT between the first lens group G1 and the second lens group G2 is 3.00mm.

[0145] Face number A4 A6 A8 A10 A12 A14 A16 S1 1.6852E-04 -1.1259E-04 3.4661E-05 -2.9397E-05 1.3434E-05 -3.6438E-06 6.4346E-07 S2 5.9584E-03 -1.5312E-03 1.5956E-04 2.3491E-05 -1.3105E-05 2.7800E-06 -3.6769E-07 S3 2.9356E-02 -1.7219E-02 5.8617E-03 -1.7371E-03 4.8344E-04 -1.1382E-04 2.0542E-05 S4 3.4739E-02 -2.1896E-02 5.9780E-03 -9.2016E-04 6.7162E-05 1.1185E-06 -3.7594E-07 S5 8.0449E-03 -4.9039E-03 1.8595E-03 -8.9325E-04 4.1079E-04 -1.4090E-04 3.4733E-05 S6 7.0602E-04 1.4030E-04 -4.6996E-04 2.7373E-04 -7.7231E-05 8.4569E-06 1.7257E-06 S7 -4.6732E-02 9.5951E-02 -9.7067E-02 7.2590E-02 -4.0992E-02 1.7319E-02 -5.3933E-03 S8 -1.1759E-01 1.4818E-01 -1.2969E-01 8.7172E-02 -4.3495E-02 1.5659E-02 -3.9355E-03 S9 -7.4081E-02 3.7573E-02 -1.9518E-02 8.2998E-03 -2.4831E-03 4.6745E-04 -4.9774E-05 S10 -1.6580E-02 3.3430E-03 -1.1577E-03 6.6780E-04 -2.6846E-04 5.5086E-05 -5.7796E-06 S11 6.6355E-03 3.5130E-03 -1.7957E-02 2.7519E-02 -2.5940E-02 1.6627E-02 -7.5288E-03 S12 7.2648E-03 -9.9287E-03 9.6920E-03 -7.7085E-03 4.4868E-03 -1.9160E-03 6.0586E-04

[0146] Table 14

[0147] Face number A18 A20 A22 A24 A26 A28 A30 S1 -7.7103E-08 6.3377E-09 -3.5250E-10 1.2691E-11 -2.6705E-13 2.4948E-15 0.0000E+00 S2 3.2713E-08 -1.9606E-09 7.5961E-11 -1.7180E-12 1.7221E-14 0.0000E+00 0.0000E+00 S3 -2.7034E-06 2.5137E-07 -1.5850E-08 6.2515E-10 -1.2400E-11 5.5369E-15 2.9843E-15 S4 -4.7595E-08 1.3466E-08 -1.1715E-09 4.7128E-11 -7.4395E-13 0.0000E+00 0.0000E+00 S5 -6.2073E-06 8.0934E-07 -7.6511E-08 5.1178E-09 -2.2979E-10 6.2079E-12 -7.6167E-14 S6 -9.0491E-07 1.8967E-07 -2.4432E-08 2.0616E-09 -1.1163E-10 3.5315E-12 -4.9702E-14 S7 1.2090E-03 -1.8689E-04 1.8123E-05 -7.9004E-07 -3.0557E-08 5.2657E-09 -1.8349E-10 S8 6.4864E-04 -5.9862E-05 1.1936E-06 2.8506E-07 -1.9351E-08 0.0000E+00 0.0000E+00 S9 2.2915E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 2.5851E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 2.4435E-03 -5.6833E-04 9.3378E-05 -1.0488E-05 7.5630E-07 -3.0901E-08 5.2326E-10 S12 -1.4216E-04 2.4584E-05 -3.0778E-06 2.6998E-07 -1.5651E-08 5.3537E-10 -8.1266E-12

[0148] Table 15

[0149] Figure 18A and Figure 20A The axial chromatic aberration curves of the optical system of Example 5 in the first mode and the second mode are respectively shown, which indicate the deviation of the convergent focus of light of different wavelengths passing through the lens. Figure 18B and Figure 20B Astigmatism curves of the optical system of Example 5 in the first mode and the second mode are shown, respectively, which represent meridional field curvature and sagittal field curvature. Figure 18C and Figure 20CThe distortion curves of the optical system of Example 5 in the first mode and the second mode are shown respectively, which represent the distortion values ​​corresponding to different field angles. 18A to 20C 、 18A to 20C It can be seen that the optical system provided in Example 5 can focus accurately, thereby achieving good imaging quality.

[0150] In summary, Examples 1 to 5 respectively satisfy the relationships shown in Table 16.

[0151] Conditional formula / Example 1 2 3 4 5 (fA-fB) / (EPDA-EPDB) 8.61 13.56 9.72 7.76 6.99 ΔT / (EPDA-EPDB) 5.21 8.18 5.24 4.54 4.03 (FG1-FG2) / (f3-f4) 1.28 1.60 1.43 1.55 1.54 f2 / (R3+R4) -1.25 -0.56 -1.48 -1.48 -0.45 TAN(FOVA) / TAN(FOVB) 1.13 1.31 1.12 1.12 1.11 FG1 / (CT1+CT2+CT3) 1.56 1.59 1.45 1.39 1.71 ∑CT / (fA-fB) 1.62 1.49 1.45 1.55 1.42 (T12+T23) / (T45+T56) 1.47 1.49 1.57 1.62 2.50 (R1+R9) / (R5-R6) 0.99 0.84 1.11 1.11 0.88 (fA / fB)×(f5 / f6) -0.50 -0.21 -1.28 -1.02 -0.87 FG2 / (CT5+CT6) -5.84 -7.33 -5.78 -7.40 -5.24 ∑CT / ΔT 2.67 2.47 2.69 2.66 2.46 (fA / fB)×ImgH(mm) 5.79 5.80 5.97 5.81 5.78

[0152] Table 16

[0153] The present application also provides an imaging device, wherein the electronic photosensitive element thereof may be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The imaging device may be a standalone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical system described above.

[0154] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of protection provided in this application is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the concept of this application. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An optical system, characterized in that It sequentially includes from the object side to the image side along the optical axis: A first lens group with positive optical power, including: a first lens, a second lens, and a third lens. Among them, the first lens has positive optical power, and its object side surface is convex; the second lens has negative optical power, its object side surface is convex, and its image side surface is concave; the third lens has positive optical power, its object side surface is convex, and its image side surface is convex; A second lens group with negative optical power, including: a fourth lens, a fifth lens, and a sixth lens. Among them, the fourth lens has negative optical power; the fifth lens has positive optical power, and its object side surface is convex; the sixth lens has negative optical power; Among them, when the object distance changes, by adjusting the distance between the second lens group and the first lens group on the optical axis, the optical system switches between a first mode and a second mode, and the focal length fA of the optical system in the first mode, the focal length fB of the optical system in the second mode, the entrance pupil diameter EPDA of the optical system in the first mode, and the entrance pupil diameter EPDB of the optical system in the second mode satisfy: 6.99 ≤ (fA - fB) / (EPDA - EPDB) < 13.6; The optical system has two lens groups with optical power; The number of lenses with optical power in the first lens group is three; The number of lenses with optical power in the second lens group is three.

2. The optical system according to claim 1, wherein The optical system satisfies: 4.0 < △T / (EPDA - EPDB) < 8.2, where △T is the change in the distance between the first lens group and the second lens group when the optical system switches from the first mode to the second mode, EPDA is the entrance pupil diameter of the optical system in the first mode, and EPDB is the entrance pupil diameter of the optical system in the second mode.

3. The optical system according to claim 1, wherein: The optical system satisfies: 1.28 ≤ (FG1 - FG2) / (f3 - f4) ≤ 1.60, where FG1 is the effective focal length of the first lens group, FG2 is the effective focal length of the second lens group, f3 is the effective focal length of the third lens, and f4 is the effective focal length of the fourth lens.

4. The optical system according to claim 1, wherein: The optical system satisfies: -1.5 < f2 / (R3 + R4) < -0.4, where f2 is the effective focal length of the second lens, R3 is the curvature radius of the object side surface of the second lens, and R4 is the curvature radius of the image side surface of the second lens.

5. The optical system according to claim 1, wherein The optical system satisfies: 1.1 < TAN(FOVA) / TAN(FOVB) ≤ 1.31, where FOVA is the maximum field angle of view of the optical system in the first mode, and FOVB is the maximum field angle of view of the optical system in the second mode.

6. The optical system according to claim 1, wherein: The optical system satisfies: 1.39 ≤ FG1 / (CT1 + CT2 + CT3) ≤ 1.71, where FG1 is the effective focal length of the first lens group, CT1 is the central thickness of the first lens on the optical axis, CT2 is the central thickness of the second lens on the optical axis, and CT3 is the central thickness of the third lens on the optical axis.

7. The optical system according to claim 1, wherein: The optical system satisfies the following: 1.4<∑CT / (fA-fB)≤1.62, where ∑CT is the sum of the center thicknesses of each lens among the first lens to the sixth lens on the optical axis, fA is the focal length of the optical system in the first mode, and fB is the focal length of the optical system in the second mode.

8. The optical system according to claim 1, wherein: The optical system satisfies the following: 1.47≤(T12+T23) / (T45+T56)≤2.50, where T12 is the air distance between the first lens and the second lens on the optical axis, T23 is the air distance between the second lens and the third lens on the optical axis, T45 is the air distance between the fourth lens and the fifth lens on the optical axis, and T56 is the air distance between the fifth lens and the sixth lens on the optical axis.

9. The optical system according to claim 1, wherein: The optical system satisfies: 0.8<(R1+R9) / (R5-R6)≤1.11, wherein R1 is the curvature radius of the object side surface of the first lens, R9 is the curvature radius of the object side surface of the fifth lens, R5 is the curvature radius of the object side surface of the third lens, and R6 is the curvature radius of the image side surface of the third lens.

10. The optical system according to any one of claims 1 to 9, wherein: The optical system satisfies: -1.3<(fA / fB)×(f5 / f6)<-0.2, where fA is the focal length of the optical system in the first mode, fB is the focal length of the optical system in the second mode, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens.

11. The optical system according to any one of claims 1 to 9, wherein: The optical system satisfies: -7.40≤FG2 / (CT5+CT6)<-5.2, where FG2 is the effective focal length of the second lens group, CT5 is the center thickness of the fifth lens on the optical axis, and CT6 is the center thickness of the sixth lens on the optical axis.

12. The optical system according to any one of claims 1 to 9, wherein: The optical system satisfies the following: 2.46≤∑CT / ΔT≤2.69, where ∑CT is the sum of the center thicknesses of each of the first to sixth lenses on the optical axis, and ΔT is a change in the spacing between the first lens group and the second lens group when the optical system switches from the first mode to the second mode.

13. The optical system according to any one of claims 1 to 9, wherein: The optical system satisfies: 5.78mm≤(fA / fB)×ImgH≤5.97mm, wherein fA is the focal length of the optical system in the first mode, fB is the focal length of the optical system in the second mode, and ImgH is half of the diagonal length of the effective pixel area on the imaging surface of the optical system.

14. The optical system according to any one of claims 1 to 9, wherein: The first lens to the sixth lens are all edge-cut lenses.

Images