Zoom lens assembly and optical system

Abstract

The application provides an expansion lens assembly and an optical system. The expansion lens assembly comprises a first lens barrel and a second lens barrel. The first lens barrel contains a first lens group. The first lens group comprises a first lens to a seventh lens. The second lens barrel contains a second lens group. The second lens group comprises an eighth lens to a twelfth lens. The second lens barrel is movable along an optical axis to realize zooming. The following conditions are met: 2.00 < (CT10+CT11+CT12) / CP10 < 2.50; 3.40 < CT11 / (D10s-d10s) < 6.80; CT10 is the center thickness of the tenth lens, CT11 is the center thickness of the eleventh lens, CT12 is the center thickness of the twelfth lens, CP10 is the maximum thickness of the tenth interval element in the direction of the optical axis, D10s is the outer diameter of the object side surface of the tenth interval element, and d10s is the inner diameter of the object side surface of the tenth interval element. The expansion lens assembly can effectively block scattered stray light.

Description

Technical Field

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

[0002] With the rapid development of digital photography, mobile terminals, and security monitoring, stringent requirements have been placed on imaging systems, demanding high resolution, high contrast, miniaturization, and lightweight design. To extend the equivalent focal length and achieve telephoto capabilities without altering the main lens structure, zoom extension lens components (e.g., teleconverter lenses / magnifiers) are typically added to the main lens optical path. These zoom extension lenses change the effective focal length of the system through a combination of multiple lenses, and their image quality directly affects the overall shooting performance of the camera.

[0003] The existing zoom extension lens has poor matching between its optical path structure and light-blocking structure, which makes stray light easy to accumulate, resulting in high image haze and low contrast. Summary of the Invention

[0004] One aspect of this application provides an extended lens assembly, which includes a first lens barrel and a second lens barrel sequentially from the object side to the image side along the optical axis. The first lens barrel contains a first lens group having positive optical power. The first lens group includes: a first lens having positive optical power, the object side of the first lens being convex and the image side of the first lens being concave; a second lens having positive optical power, the object side of the second lens being convex and the image side of the second lens being convex; a third lens having negative optical power, the object side of the third lens being concave and the image side of the third lens being concave; and a lens having positive optical power. A fourth lens with positive optical power, wherein the object-side surface of the fourth lens is convex and the image-side surface of the fourth lens is concave; 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 concave; a sixth lens with negative optical power, wherein the object-side surface of the sixth lens is convex and the image-side surface of the sixth lens is concave; 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 convex; the second lens barrel contains a second lens group having positive optical power, the second lens group including: an eighth lens with negative optical power, wherein the object-side surface of the eighth lens is... The image-side surface of the eighth lens is concave; the object-side surface of the ninth lens is convex, and the image-side surface of the ninth lens is convex; the object-side surface of the tenth lens is concave, and the image-side surface of the tenth lens is concave; the object-side surface of the eleventh lens is convex, and the image-side surface of the eleventh lens is convex; the object-side surface of the twelfth lens is convex, and the image-side surface of the twelfth lens is convex; the first lens to the twelfth lens are arranged sequentially from the object-side to the image-side, and the tenth lens... A tenth spacer element is provided on the image-side surface of the lens; wherein the second lens barrel can move along the optical axis to achieve zoom; and satisfies: 2.00 < (CT10 + CT11 + CT12) / CP10 < 2.50; 3.40 < CT11 / (D10s - d10s) < 6.80; CT10 is the center thickness of the tenth lens, CT11 is the center thickness of the eleventh lens, CT12 is the center thickness of the twelfth lens, CP10 is the maximum thickness of the tenth spacer element along the optical axis, D10s is the outer diameter of the object-side surface of the tenth spacer element, and d10s is the inner diameter of the object-side surface of the tenth spacer element.

[0005] According to an embodiment of this application, the extended lens assembly satisfies: 11.11≤L2 / ΔT≤13.95, where L2 is the maximum thickness of the second lens barrel along the optical axis, and ΔT is the distance the second lens barrel moves along the optical axis when the extended lens assembly changes from an infinite object distance state to a 1000mm object distance state.

[0006] According to an embodiment of this application, a first spacer element is provided on the image side of the first lens, and the extended lens assembly satisfies: 5.05 < d1s / T12 < 6.10, where d1s is the inner diameter of the object side of the first spacer element, and T12 is the air gap between the first lens and the second lens on the optical axis.

[0007] According to an embodiment of this application, a first spacer element is provided on the image-side surface of the first lens, and the extended lens assembly satisfies: 3.00≤CP1 / (D1m-d1m)≤7.15, where CP1 is the maximum thickness of the first spacer element along the optical axis direction, d1m is the inner diameter of the image-side surface of the first spacer element, and D1m is the outer diameter of the image-side surface of the first spacer element.

[0008] According to an embodiment of this application, a sixth spacer element is provided on the image-side surface of the sixth lens, and the extended lens assembly satisfies: 1.60 < LG1 / (D6s + D6m) < 2.15, where LG1 is the axial distance from the object-side surface of the first lens to the image-side surface of the seventh lens, D6s is the outer diameter of the object-side surface of the sixth spacer element, and D6m is the outer diameter of the image-side surface of the sixth spacer element.

[0009] According to an embodiment of this application, a third spacer element is provided on the image-side surface of the third lens, and the extended lens assembly satisfies: -11.40≤F23 / (D3s-d3s)≤-5.65, where F23 is the combined focal length of the second lens and the third lens, D3s is the outer diameter of the object-side surface of the third spacer element, and d3s is the inner diameter of the object-side surface of the third spacer element.

[0010] According to an embodiment of this application, a lens barrel auxiliary element is provided on the object side of the first lens, and the extended lens assembly satisfies: 1.05≤F1234 / (d0bs+D0bs)≤1.99, where F1234 is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, d0bs is the inner diameter of the object side of the lens barrel auxiliary element, and D0bs is the outer diameter of the object side of the lens barrel auxiliary element.

[0011] According to an embodiment of this application, a fifth spacer element is provided on the image-side surface of the fifth lens; a sixth spacer element is provided on the image-side surface of the sixth lens, and the extended lens assembly satisfies: 1.81≤(CT6+T67) / (CP5+CP6)≤2.50, where CT6 is the center thickness of the sixth lens, T67 is the air gap between the sixth lens and the seventh lens on the optical axis, CP5 is the maximum thickness of the fifth spacer element along the optical axis, and CP6 is the maximum thickness of the sixth spacer element along the optical axis.

[0012] According to an embodiment of this application, the extended lens assembly satisfies: 1.90≤L1 / (∑CTG1+∑CTG2)<2.45, where L1 is the maximum thickness of the first lens barrel along the optical axis, ∑CTG1 is the sum of the center thicknesses of all lenses from the first lens to the seventh lens, and ∑CTG2 is the sum of the center thicknesses of all lenses from the eighth lens to the twelfth lens.

[0013] According to an embodiment of this application, an eighth spacer element is provided on the image-side surface of the eighth lens, and the extended lens assembly satisfies: 1.85 < LG2 / d8s < 3.50, where LG2 is the axial distance from the object-side surface of the eighth lens to the image-side surface of the twelfth lens, and d8s is the inner diameter of the object-side surface of the eighth spacer element.

[0014] According to an embodiment of this application, a fifth spacer element is provided on the image-side surface of the fifth lens; a sixth spacer element is provided on the image-side surface of the sixth lens, and the extended lens assembly satisfies: 1.15 < (d5s + d5m) / (d6s + d6m) < 1.80, where d5s is the inner diameter of the object-side surface of the fifth spacer element, d5m is the inner diameter of the image-side surface of the fifth spacer element, d6s is the inner diameter of the object-side surface of the sixth spacer element, and d6m is the inner diameter of the image-side surface of the sixth spacer element.

[0015] According to an embodiment of this application, the extended lens assembly satisfies: 5.90 < F101112 / CP10 < 8.15, where F101112 is the combined focal length of the tenth lens, the eleventh lens, and the twelfth lens, and CP10 is the maximum thickness of the tenth spacer element along the optical axis.

[0016] According to an embodiment of this application, a lens barrel auxiliary element is provided on the object side of the first lens, and the extended lens assembly satisfies: 1.55 < CT1 / CP0b < 2.85, where CT1 is the center thickness of the first lens and CP0b is the maximum thickness of the lens barrel auxiliary element along the optical axis.

[0017] According to an embodiment of this application, a first spacer element is provided on the image-side surface of the first lens, and a fifth spacer element is provided on the image-side surface of the fifth lens. The extended lens assembly satisfies: 1.15 < FG1 / (D1s+D5s) < 1.55, where FG1 is the combined focal length of the first lens group, D1s is the outer diameter of the object-side surface of the first spacer element, and D5s is the outer diameter of the object-side surface of the fifth spacer element.

[0018] Another aspect of this application provides an optical system comprising: an extended lens assembly as described in any of the claims of this application; an imaging lens located on the image side of the twelfth lens; and an imaging surface, wherein an outgoing light beam from the extended lens assembly enters the imaging lens to image on the imaging surface using the imaging lens, and an eighth spacer element is provided on the image side of the eighth lens, wherein the extended lens assembly satisfies: 1.25 < FG2 / d8m < 1.95, where FG2 is the combined focal length of the second lens group, and d8m is the inner diameter of the image side of the eighth spacer element.

[0019] According to the technical solution of this application embodiment, under the premise of 2.00 < (CT10 + CT11 + CT12) / CP10 < 2.50, stray light problems are easily generated between the tenth and eleventh lenses in the extended lens assembly. By constraining the range of 3.40 < CT11 / (D10s - d10s) < 6.80, the inner and outer diameters of the tenth spacer element are reasonably designed, which can effectively block the stray light reflected from the edge of the tenth lens and the scattered stray light transmitted from the front lens group, and no obvious stray light is generated. When the lower limit of CT11 / (D10s - d10s) is exceeded, the radial baffle of the tenth spacer element is too wide and the light-transmitting inner diameter is too small, and the step reflection of the spacer element generates arc-shaped diffuse large spot stray light. When the upper limit of CT11 / (D10s - d10s) is exceeded, the radial baffle width of the tenth spacer element is insufficient, the light blocking fails, and a large number of discrete point stray lights appear on the image plane. Attached Figure Description

[0020] 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:

[0021] Figure 1 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when (CT10+CT11+CT12) / CP10=2.20 and CT11 / (D10s-d10s)=3.05. Figure 2The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when (CT10+CT11+CT12) / CP10=2.20 and CT11 / (D10s-d10s)=5.6. Figure 3 The stray light spot diagram of the extended lens assembly provided in at least one embodiment of this application is shown when (CT10+CT11+CT12) / CP10=2.20 and CT11 / (D10s-d10s)=7.4. Figure 4 and Figure 5 A schematic diagram showing the dimensions of an extended lens assembly of this application is provided. Figure 6 This application provides a schematic diagram of the overall architecture of an optical system. Figure 7 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly of 1 in its first state; Figure 8 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 9 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly in the first state. Figure 10 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 11 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly of 3 in its first state; Figure 12 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly of 3 in the second state; Figure 13 A schematic diagram of the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 1 in the first state is shown. Figure 14 A schematic diagram showing the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 1 in the second state is shown. Figure 15 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly of 1 in its first state; Figure 16 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 17 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly in the first state; Figure 18 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 19 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly of 3 in its first state; Figure 20 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly of 3 in the second state; Figure 21 A schematic diagram of the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 2 in the first state is shown. Figure 22 A schematic diagram of the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 2 in the second state is shown. Figure 23 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly of 1 in its first state; Figure 24 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 25 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly in the first state; Figure 26 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 27 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly of 3 in its first state; Figure 28 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly of 3 in the second state; Figure 29 A schematic diagram showing the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 3 in its first state is shown; and Figure 30A schematic diagram of the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 3 in the second state is shown. Detailed Implementation

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] The features, principles and other aspects of this application are described in detail below.

[0030] An extended lens assembly according to an exemplary embodiment of this application includes, sequentially from the object side to the image side along the optical axis, a first lens barrel and a second lens barrel. The first lens barrel contains a first lens group having positive optical power. The first lens group includes: a first lens having positive optical power, the object side of the first lens being convex and the image side being concave; a second lens having positive optical power, the object side of the second lens being convex and the image side being convex; a third lens having negative optical power, the object side of the third lens being concave and the image side being concave; and a lens having positive optical power. The fourth lens has a convex object-side surface and a concave image-side surface; the fifth lens has positive optical power, also with a convex object-side surface and a concave image-side surface; the sixth lens has negative optical power, with a convex object-side surface and a concave image-side surface; the seventh lens has negative optical power, with a concave object-side surface and a convex image-side surface; the second lens barrel contains a second lens group with positive optical power, which includes: an eighth lens with negative optical power, having a concave object-side surface. The image-side surface of the eighth lens is concave; the ninth lens, with positive optical power, has a convex object-side surface and a convex image-side surface; the tenth lens, with negative optical power, has a concave object-side surface and a concave image-side surface; the eleventh lens, with positive optical power, has a convex object-side surface and a convex image-side surface; the twelfth lens, with positive optical power, has a convex object-side surface and a convex image-side surface; the first to twelfth lenses are arranged sequentially from the object-side to the image-side, with the tenth lens positioned on its image-side surface. There is a tenth spacer element; wherein, the second lens barrel can move along the optical axis to achieve zoom; and satisfies: 2.00<(CT10+CT11+CT12) / CP10<2.50; 3.40<CT11 / (D10s-d10s)<6.80; CT10 is the center thickness of the tenth lens, CT11 is the center thickness of the eleventh lens, CT12 is the center thickness of the twelfth lens, CP10 is the maximum thickness of the tenth spacer element along the optical axis, D10s is the outer diameter of the object side of the tenth spacer element, and d10s is the inner diameter of the object side of the tenth spacer element.

[0031] Figure 1 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when (CT10+CT11+CT12) / CP10=2.20 and CT11 / (D10s-d10s)=3.05. Figure 2 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when (CT10+CT11+CT12) / CP10=2.20 and CT11 / (D10s-d10s)=5.6. Figure 3 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when (CT10+CT11+CT12) / CP10=2.20 and CT11 / (D10s-d10s)=7.4.

[0032] like Figure 1 As shown, the stray light spot pattern was obtained under the conditions of (CT10+CT11+CT12) / CP10=2.20 and CT11 / (D10s-d10s)=3.05. Figure 1 In the image, a large number of diffuse stray light spots are distributed outside the central target area. These spots are large in area and high in brightness. In some areas, the spots overlap, blurring the target outline.

[0033] like Figure 2 As shown, the spot pattern was obtained under the conditions of (CT10+CT11+CT12) / CP10=2.20 and CT11 / (D10s-d10s)=5.6. Figure 2 The central target in the image is clear, with only a very small amount of faint stray light at the very edge. The light spots are almost invisible, and the overall image is clean, with high contrast and complete detail.

[0034] like Figure 3 As shown, the spot pattern was obtained under the conditions of (CT10+CT11+CT12) / CP10=2.20 and CT11 / (D10s-d10s)=7.4. Figure 3 Dense, dotted stray lights appear at the edges and around the center of the image, with numerous and unevenly distributed light spots, resulting in poor overall image clarity and severe loss of detail.

[0035] Therefore, under the premise of 2.00 < (CT10 + CT11 + CT12) / CP10 < 2.50, this application, by constraining the range of 3.40 < CT11 / (D10s - d10s) < 6.80, rationally designs the inner and outer diameters of the tenth spacer element, which can effectively block the stray light reflected from the edge of the tenth lens and the scattered stray light transmitted from the front lens group, without generating obvious stray light. When the lower limit of CT11 / (D10s - d10s) is exceeded by 3.40, the radial baffle of the tenth spacer element is too wide and the light-transmitting inner diameter is too small, and the step reflection of the spacer element produces arc-shaped diffuse large spot stray light; when the upper limit of CT11 / (D10s - d10s) is exceeded by 6.80, the radial baffle width of the tenth spacer element is insufficient, the light blocking fails, and a large number of discrete point stray lights appear on the image plane.

[0036] In an exemplary embodiment, the extended lens assembly satisfies: 11.11 ≤ L2 / ΔT ≤ 13.95, where L2 is the maximum thickness of the second lens barrel along the optical axis, and ΔT is the distance the second lens barrel moves along the optical axis when the extended lens assembly changes from an infinite object distance to a 1000mm object distance. This embodiment reasonably controls the range of this condition, ensuring no stray light spots and stable contrast in imaging at different object distances, while optimizing zoom motion characteristics, improving focusing smoothness and accuracy, and balancing lens miniaturization and assembly reliability.

[0037] In an exemplary embodiment, a first spacer element is provided on the image-side surface of the first lens, and the extended lens assembly satisfies: 5.05 < d1s / T12 < 6.10, where d1s is the inner diameter of the object-side surface of the first spacer element, and T12 is the air gap between the first lens and the second lens on the optical axis. This embodiment reasonably controls the range of this condition, which can both intercept stray light incident from the front end in advance through the first spacer element, improving the image haze throughout the process, and stabilize the coaxiality of the front lens group, suppressing ghosting and vignetting problems in the front optical path, thus balancing optical imaging quality and lens assembly yield.

[0038] In an exemplary embodiment, a first spacer element is provided on the image-side surface of the first lens, and the extended lens assembly satisfies: 3.00≤CP1 / (D1m-d1m)≤7.15, where CP1 is the maximum thickness of the first spacer element along the optical axis, d1m is the inner diameter of the image-side surface of the first spacer element, and D1m is the outer diameter of the image-side surface of the first spacer element. This embodiment reasonably controls the range of this condition, forming an axial and radial cooperative light-blocking structure in the front optical path, intercepting stray light from the source, and simultaneously providing stable positioning for the front lens, reducing the risk of lens eccentricity, balancing light transmission and lens miniaturization design, and improving mass production assembly yield.

[0039] In an exemplary embodiment, a sixth spacer element is provided on the image-side surface of the sixth lens, extending the lens assembly to satisfy: 1.60 < LG1 / (D6s + D6m) < 2.15, where LG1 is the axial distance from the object-side surface of the first lens to the image-side surface of the seventh lens, D6s is the outer diameter of the object-side surface of the sixth spacer element, and D6m is the outer diameter of the image-side surface of the sixth spacer element. This embodiment reasonably controls the range of this conditional expression, synergistically constraining the front and middle optical path space and the radial light-blocking size of the sixth spacer element, effectively intercepting stray light generated by the sixth and seventh lenses, suppressing imaging stray light and ghosting under full zoom conditions, while optimizing the front group structure size, balancing lens miniaturization and the coaxial accuracy of the middle lens assembly.

[0040] In an exemplary embodiment, a third spacer element is provided on the image-side surface of the third lens, and the extended lens assembly satisfies: -11.40≤F23 / (D3s-d3s)≤-5.65, where F23 is the combined focal length of the second and third lenses, D3s is the outer diameter of the object-side surface of the third spacer element, and d3s is the inner diameter of the object-side surface of the third spacer element. This embodiment reasonably controls the range of this condition, relies on the combination of positive and negative lenses to converge large-angle stray light, and works with the third spacer element to achieve mid-section light blocking, reducing stray light from converging to subsequent lenses, improving imaging haze under all conditions, optimizing the aberration correction effect of the front lens group, improving the coaxial accuracy of the mid-section lens assembly, and balancing light transmission performance and stray light suppression capability.

[0041] In an exemplary embodiment, a lens barrel auxiliary element is provided on the object-side surface of the first lens, and the extended lens assembly satisfies: 1.05≤F1234 / (d0bs+D0bs)≤1.99, where F1234 is the combined focal length of the first, second, third, and fourth lenses, d0bs is the inner diameter of the object-side surface of the lens barrel auxiliary element, and D0bs is the outer diameter of the object-side surface of the lens barrel auxiliary element. This embodiment reasonably controls this conditional range, and by combining the front-end optical convergent beam with the front-end light-blocking structure, it intercepts obliquely incident stray light from the incident source, improves imaging stray light under full zoom, and balances the light transmission illuminance and light-blocking effect, taking into account both lens miniaturization and front-end lens assembly stability.

[0042] In an exemplary embodiment, a fifth spacer element is provided on the image-side surface of the fifth lens; a sixth spacer element is provided on the image-side surface of the sixth lens. The extended lens assembly satisfies: 1.81≤(CT6+T67) / (CP5+CP6)≤2.50, where CT6 is the center thickness of the sixth lens, T67 is the air gap between the sixth and seventh lenses on the optical axis, CP5 is the maximum thickness of the fifth spacer element along the optical axis, and CP6 is the maximum thickness of the sixth spacer element along the optical axis. This embodiment reasonably controls the range of this conditional expression, sets a continuous axial light-blocking structure in the middle section of the lens, effectively intercepts the scattered stray light generated by the sixth and seventh lenses, and at the same time achieves reliable axial clamping of the sixth and seventh lenses, reducing the risk of lens eccentricity and light leakage, and taking into account both compact lens design and mass assembly yield.

[0043] In an exemplary embodiment, the extended lens assembly satisfies: 1.90 ≤ L1 / (∑CTG1+∑CTG2) < 2.45, where L1 is the maximum thickness of the first lens barrel along the optical axis, ∑CTG1 is the sum of the center thicknesses of all lenses from the first to the seventh lens, and ∑CTG2 is the sum of the center thicknesses of all lenses from the eighth to the twelfth lens. This embodiment reasonably controls the range of this conditional expression, coordinates the thickness of the two sets of lenses and the accommodating space of the first lens barrel, balances the optical path gap to reduce the amount of stray light generated across the entire field of view, ensures haze-free imaging at full zoom, and optimizes the lens assembly state to avoid compression deformation and eccentric light leakage, while taking into account both the miniaturization design of the extended lens and the stability of mass production.

[0044] In an exemplary embodiment, an eighth spacer element is provided on the image-side surface of the eighth lens, and the extended lens assembly satisfies: 1.85 < LG2 / d8s < 3.50, where LG2 is the axial distance from the object-side surface of the eighth lens to the image-side surface of the twelfth lens, and d8s is the inner diameter of the object-side surface of the eighth spacer element. This embodiment reasonably controls the range of this condition, effectively intercepting stray light from the edges transmitted by the front group, while balancing the light transmission performance and structural compactness of the rear group, avoiding vignetting and light leakage defects, and optimizing the assembly accuracy and mass production stability of the rear group.

[0045] In an exemplary embodiment, a fifth spacer element is provided on the image-side surface of the fifth lens; a sixth spacer element is provided on the image-side surface of the sixth lens, and the extended lens assembly satisfies: 1.15 < (d5s + d5m) / (d6s + d6m) < 1.80, where d5s is the inner diameter of the object-side surface of the fifth spacer element, d5m is the inner diameter of the image-side surface of the fifth spacer element, d6s is the inner diameter of the object-side surface of the sixth spacer element, and d6m is the inner diameter of the image-side surface of the sixth spacer element. This embodiment reasonably controls the range of this conditional expression, so that a gradient light-passing and light-blocking structure is formed in the middle section of the optical path, which can not only intercept stray light in the middle section step by step, but also optimize the coaxial accuracy and mass production stability of the middle lens assembly, thus ensuring the lightweight and miniaturized characteristics of the lens while achieving high imaging quality.

[0046] In an exemplary embodiment, the extended lens assembly satisfies: 5.90 < F101112 / CP10 < 8.15, where F101112 is the combined focal length of the tenth, eleventh, and twelfth lenses, and CP10 is the maximum thickness of the tenth spacer element along the optical axis. This embodiment reasonably controls this conditional range, relying on the rear end lens to converge the scattered light beam, and in conjunction with the tenth spacer element to form a deep light-blocking barrier, doubly intercepting stray light around the eleventh lens, while optimizing the aberration performance of the rear end, balancing light-blocking performance with the compactness of the zoom lens barrel, and improving the stability of lens assembly.

[0047] In an exemplary embodiment, a lens barrel auxiliary element is provided on the object side of the first lens, and the extended lens assembly satisfies: 1.55 < CT1 / CP0b < 2.85, where CT1 is the center thickness of the first lens and CP0b is the maximum thickness of the lens barrel auxiliary element along the optical axis. This embodiment reasonably controls the range of this condition, and achieves beam constraint and front-end light blocking at the lens incident end, intercepting external stray light from the source, improving the haze of the image under full zoom conditions, while stabilizing the axial assembly state of the first lens, avoiding lens compression deformation or eccentric light leakage, and balancing the front-end light blocking effect with the compact lens design.

[0048] In an exemplary embodiment, a first spacer element is provided on the image-side surface of the first lens, and a fifth spacer element is provided on the image-side surface of the fifth lens. The extended lens assembly satisfies: 1.15 < FG1 / (D1s+D5s) < 1.55, where FG1 is the combined focal length of the first lens group, D1s is the outer diameter of the object-side surface of the first spacer element, and D5s is the outer diameter of the object-side surface of the fifth spacer element. This embodiment reasonably controls the range of this conditional expression, achieving coordinated cooperation between the front group beam convergence and segmented radial light blocking, progressively intercepting scattered stray light generated by the front group lens, while optimizing the assembly and limiting effect of the front group lens, balancing the light transmission illuminance and the compact lens design.

[0049] In an exemplary embodiment, an eighth spacer element is provided on the image-side surface of the eighth lens, extending the lens assembly to satisfy: 1.25 < FG2 / d8m < 1.95, where FG2 is the combined focal length of the second lens group, and d8m is the inner diameter of the image-side surface of the eighth spacer element. This embodiment reasonably controls this conditional range, intercepting scattered stray light transmitted from the front lens group, improving image haze in full zoom conditions, while optimizing the coaxial accuracy of the rear front lens assembly, balancing light transmission and compact zoom lens barrel design, and improving image consistency.

[0050] Another aspect of this disclosure provides an optical system including an extended lens assembly, an imaging lens, and an imaging surface as provided in any embodiment of this disclosure. The imaging lens is located on the image side of the twelfth lens; the outgoing beam of the extended lens assembly enters the imaging lens to image on the imaging surface using the imaging lens; an eighth spacer element is provided on the image side of the eighth lens; the extended lens assembly satisfies: 1.25 < FG2 / d8m < 1.95, where FG2 is the combined focal length of the second lens group, and d8m is the inner diameter of the image side of the eighth spacer element.

[0051] Figure 4 and Figure 5 A schematic diagram showing the dimensions of an extended lens assembly of this application is provided.

[0052] Figure 4The diagram clearly shows the following parameters: the maximum thickness L1 of the first lens barrel along the optical axis, the maximum thickness L2 of the second lens barrel along the optical axis, the outer diameter D0bs of the object side of the lens barrel auxiliary element, the outer diameter D1s of the object side of the first spacer element, the inner diameter d0bs of the object side of the lens barrel auxiliary element, the inner diameter d1s of the object side of the first spacer element, the outer diameter D3s of the object side of the third spacer element, the inner diameter d3s of the object side of the third spacer element, the inner diameter d8s of the object side of the eighth spacer element, the outer diameter D5s of the object side of the fifth spacer element, the inner diameter d5s of the object side of the fifth spacer element, the outer diameter D6s of the object side of the sixth spacer element, the inner diameter d6s of the object side of the sixth spacer element, the outer diameter D10s of the object side of the tenth spacer element, and the inner diameter d10s of the object side of the tenth spacer element, so as to clearly and intuitively understand the meaning of these parameters.

[0053] Figure 5 The diagram clearly shows the outer diameter D1m of the image side of the first spacer element, the inner diameter d1m of the image side of the first spacer element, the inner diameter d5m of the image side of the fifth spacer element, the outer diameter D6m of the image side of the sixth spacer element, the inner diameter d6m of the image side of the sixth spacer element, the inner diameter d8m of the image side of the eighth spacer element, the maximum thickness CP0b of the lens barrel auxiliary element along the optical axis, the maximum thickness CP1 of the first spacer element along the optical axis, the maximum thickness CP5 of the fifth spacer element along the optical axis, the maximum thickness CP6 of the sixth spacer element along the optical axis, and the maximum thickness CP10 of the tenth spacer element along the optical axis, etc., to provide a clear and intuitive understanding of the meaning of these parameters.

[0054] To facilitate the description of the extended lens assembly and the surface shape of the specific lens, these parameters will not be shown in the accompanying drawings when describing specific embodiments.

[0055] Figure 6 A schematic diagram of the overall architecture of an optical system provided in this application is shown.

[0056] like Figure 6 As shown, the optical system includes an extended lens assembly 10, an imaging lens 20, and an imaging surface IMG. The extended lens assembly 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. The extended lens assembly 10 is an extended lens assembly provided in any embodiment of this disclosure.

[0057] The extended lens assembly 10 includes a first lens barrel and a second lens barrel sequentially from the object side to the image side along the optical axis. The first lens barrel includes a first lens group G1, and the second lens barrel includes a second lens group G2. The first lens group G1 has positive optical power, and the second lens group G2 has positive optical power.

[0058] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a seventh lens E7. The first lens E1 has positive optical power, its object-side surface is convex, and its image-side surface is concave. The second lens E2 has positive optical power, its object-side surface is convex, and its image-side surface is convex. The third lens E3 has negative optical power, its object-side surface is concave, and its image-side surface is concave. The fourth lens E4 has positive optical power, its object-side surface is convex, and its image-side surface is concave. The fifth lens E5 has positive optical power, its object-side surface is convex, and its image-side surface is concave. The sixth lens E6 has negative optical power, its object-side surface is convex, and its image-side surface is concave. The seventh lens E7 has negative optical power, its object-side surface is concave, and its image-side surface is convex.

[0059] The second lens group G2 includes an eighth lens E8, a ninth lens E9, a tenth lens E10, an eleventh lens E11, and a twelfth lens E12. The eighth lens E8 has negative optical power, and both its object-side and image-side surfaces are concave. The ninth lens E9 has positive optical power, and both its object-side and image-side surfaces are convex. The tenth lens E10 has negative optical power, and both its object-side and image-side surfaces are concave. The eleventh lens E11 has positive optical power, and both its object-side and image-side surfaces are convex. The twelfth lens E12 has positive optical power, and both its object-side and image-side surfaces are convex.

[0060] A tenth spacer element is provided on the image side of the tenth lens E10; the second lens barrel can move along the optical axis to achieve zoom; and satisfies: 2.00 < (CT10 + CT11 + CT12) / CP10 < 2.50; 3.40 < CT11 / (D10s - d10s) < 6.80; CT10 is the center thickness of the tenth lens, CT11 is the center thickness of the eleventh lens, CT12 is the center thickness of the twelfth lens, CP10 is the maximum thickness of the tenth spacer element along the optical axis, D10s is the outer diameter of the object side of the tenth spacer element, and d10s is the inner diameter of the object side of the tenth spacer element.

[0061] For example, light from an object passes sequentially through the corresponding surfaces of the first lens group G1, the second lens group G2, and the imaging lens 20, and is finally imaged on the imaging surface IMG.

[0062] The following description, with reference to the accompanying drawings, further illustrates examples of the specific surface shape and parameters of the extended lens assembly applicable to the above embodiments.

[0063] It should be noted that Example 1 exists in the following Example 1. 1. Example 1 2. Example 1 Three examples in 3, Example 2 contains Example 2. 1. Example 2 2. Example 2 Three examples are given in Example 3, with Example 3 existing in Example 3. 1. Example 3 2. Example 3 Three examples of 3. In the three examples of the same embodiment, some optical parameters of the extended lens assembly are the same. For example, the radius of curvature, center thickness and other parameters of the first to twelfth lenses of the extended lens assembly may be the same, but the parameters shown, such as the thickness, inner diameter and outer diameter of the lens barrel and the first spacer element, may be different.

[0064] It should be noted that any one of the examples in Embodiments 1 to 3 described below is applicable to all implementations of this application.

[0065] Example 1 like Figures 7 to 14 As shown, the extended lens assembly of Embodiment 1 is described. Figure 7 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly in the first state. Figure 8 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 9 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly in the first state. Figure 10 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 11 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly of component 3 in its first state. Figure 12 Embodiment 1 provided in this application is shown. A schematic diagram of the extended lens assembly of 3 in the second state.

[0066] In the embodiments of this application, the first state is, for example, an infinite object distance state, and the second state is, for example, a 1000mm object distance state.

[0067] Example 1 includes 12 lenses. The effective focal lengths fq (at infinite object distance) and fw (at 1000mm object distance) of the optical system in Example 1 are both effective focal lengths when adapted to an imaging lens with a focal length of 22.48mm. The specific data for fq and fw in Example 1 are shown in the table below.

[0068] like Figures 7 to 12 As shown, the extended lens assembly according to an exemplary embodiment of this application includes a first lens barrel PM and a second lens barrel PN. The first lens barrel PM includes a first lens group G1 (participating in...). Figure 6 The second lens tube PN includes the second lens group G2 (participating in...). Figure 6 The first lens group G1 has positive optical power, and the second lens group G2 has positive optical power.

[0069] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a seventh lens E7.

[0070] 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 concave.

[0071] The second lens E2 has positive optical power. The object side S3 of the second lens E2 is convex, and the image side S4 of the second lens E2 is convex.

[0072] The third lens E3 has negative optical power. The object side S4 of the third lens E3 is concave, and the image side S5 of the third lens E3 is concave.

[0073] The fourth lens E4 has positive optical power. The object side S6 of the fourth lens E4 is convex, and the image side S7 of the fourth lens E4 is concave.

[0074] The fifth lens E5 has positive optical power. The object side S8 of the fifth lens E5 is convex, and the image side S9 of the fifth lens E5 is concave.

[0075] The sixth lens E6 has negative optical power. The object side S10 of the sixth lens E6 is convex, and the image side S11 of the sixth lens E6 is concave.

[0076] The seventh lens E7 has negative optical power. The object side surface S12 of the seventh lens E7 is concave, and the image side surface S13 of the seventh lens E7 is convex.

[0077] The second lens group G2 includes the eighth lens E8, the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0078] The eighth lens E8 has negative optical power. The object side S14 of the eighth lens E8 is concave, and the image side S15 of the eighth lens E8 is concave.

[0079] The ninth lens E9 has positive optical power. The object-side surface S16 of the ninth lens E9 is convex, and the image-side surface S17 of the ninth lens E9 is convex.

[0080] The tenth lens E10 has negative optical power. The object side S18 of the tenth lens E10 is concave, and the image side S19 of the tenth lens E10 is concave.

[0081] The eleventh lens E11 has positive optical power. The object-side surface S19 of the eleventh lens E11 is convex, and the image-side surface S20 of the eleventh lens E11 is convex.

[0082] The twelfth lens E12 has positive optical power. The object side S21 of the twelfth lens E12 is convex, and the image side S22 of the twelfth lens E12 is convex.

[0083] An auxiliary element P0b is provided on the object side S1 of the first lens E1; a first spacer element P1 is provided on the image side S2 of the first lens E1; a third spacer element P3 is provided on the image side S5 of the third lens E3; a fifth spacer element P5 is provided on the image side S9 of the fifth lens E5; a sixth spacer element P6 is provided on the image side S11 of the sixth lens E6; an eighth spacer element P8 is provided on the image side S15 of the eighth lens E8; and a tenth spacer element P10 is provided on the image side S19 of the tenth lens E10.

[0084] In this embodiment, the second lens E2 and the third lens E3 are cemented together, and the tenth lens E10 and the eleventh lens E11 are cemented together.

[0085] Figures 7 to 12 In the examples 1-1, 1-2 and 1-3, the extended lens assemblies have the same surface type, radius of curvature, thickness, refractive index and Abbe number.

[0086] The basic parameters of the extended lens assembly 10 in the following embodiment are shown in Table 1. The values ​​of D1, D2, and D3 in Table 1 are shown in Table 2.

[0087] Table 1

[0088] Table 2

[0089] Figure 13 A schematic diagram showing the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 1 in its first state is illustrated. Figure 13As shown, the optical system given in Example 1 can achieve good imaging quality in the first state.

[0090] Figure 14 A schematic diagram showing the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 1 in the second state is illustrated. Figure 14 As shown, the optical system given in Example 1 can achieve good imaging quality in the second state.

[0091] Example 2 like Figures 15 to 22 As shown, the extended lens assembly of Embodiment 2 is described. Figure 15 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly in the first state. Figure 16 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 17 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly in the first state. Figure 18 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 19 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly of component 3 in its first state. Figure 20 Embodiment 2 provided in this application is shown. A schematic diagram of the extended lens assembly of 3 in the second state.

[0092] Example 2 includes 12 lenses. The effective focal lengths fq (at infinite object distance) and fw (at 1000mm object distance) of the optical system in Example 2 are both effective focal lengths when adapted to an imaging lens with a focal length of 22.48mm. The specific data for fq and fw in Example 2 are shown in the table below.

[0093] like Figures 15 to 20 As shown, the extended lens assembly according to an exemplary embodiment of this application includes a first lens barrel PM and a second lens barrel PN. The first lens barrel PM includes a first lens group G1 (participating in...). Figure 6 The second lens tube PN includes the second lens group G2 (participating in...). Figure 6 The first lens group G1 has positive optical power, and the second lens group G2 has positive optical power.

[0094] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a seventh lens E7.

[0095] 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 concave.

[0096] The second lens E2 has positive optical power. The object side S3 of the second lens E2 is convex, and the image side S4 of the second lens E2 is convex.

[0097] The third lens E3 has negative optical power. The object side S4 of the third lens E3 is concave, and the image side S5 of the third lens E3 is concave.

[0098] The fourth lens E4 has positive optical power. The object side S5 of the fourth lens E4 is convex, and the image side S6 of the fourth lens E4 is concave.

[0099] The fifth lens E5 has positive optical power. The object side S7 of the fifth lens E5 is convex, and the image side S8 of the fifth lens E5 is concave.

[0100] The sixth lens E6 has negative optical power. The object side S9 of the sixth lens E6 is convex, and the image side S10 of the sixth lens E6 is concave.

[0101] The seventh lens E7 has negative optical power. The object-side surface S11 of the seventh lens E7 is concave, and the image-side surface S12 of the seventh lens E7 is convex.

[0102] The second lens group G2 includes the eighth lens E8, the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0103] The eighth lens E8 has negative optical power. The object side S13 of the eighth lens E8 is concave, and the image side S14 of the eighth lens E8 is concave.

[0104] The ninth lens E9 has positive optical power. The object-side surface S15 of the ninth lens E9 is convex, and the image-side surface S16 of the ninth lens E9 is convex.

[0105] The tenth lens E10 has negative optical power. The object side S17 of the tenth lens E10 is concave, and the image side S18 of the tenth lens E10 is concave.

[0106] 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.

[0107] The twelfth lens E12 has positive optical power. The object-side surface S20 of the twelfth lens E12 is convex, and the image-side surface S21 of the twelfth lens E12 is convex.

[0108] An auxiliary element P0b is provided on the object side S1 of the first lens E1; a first spacer element P1 is provided on the image side S2 of the first lens E1; a third spacer element P3 is provided on the image side S5 of the third lens E3; a fifth spacer element P5 is provided on the image side S8 of the fifth lens E5; a sixth spacer element P6 is provided on the image side S10 of the sixth lens E6; an eighth spacer element P8 is provided on the image side S14 of the eighth lens E8; and a tenth spacer element P10 is provided on the image side S18 of the tenth lens E10.

[0109] In this embodiment, the second lens E2, the third lens E3, and the fourth lens E4 are cemented together, and the tenth lens E10 and the eleventh lens E11 are cemented together.

[0110] Figures 15 to 20 In the examples 2-1, 2-2 and 2-3, the extended lens assemblies have the same surface type, radius of curvature, thickness, refractive index and Abbe number.

[0111] The basic parameters of the extended lens assembly 10 in Embodiment 2 are shown in Table 3. The values ​​of D1, D2, and D3 in Table 1 are shown in Table 4.

[0112] Table 3

[0113] Table 4

[0114] Figure 21 A schematic diagram showing the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 2 in its first state is illustrated. Figure 21 As shown, the optical system given in Embodiment 2 can achieve good imaging quality in the first state.

[0115] Figure 22 A schematic diagram showing the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 2 in the second state is illustrated. Figure 22 As shown, the optical system given in Embodiment 2 can achieve good imaging quality in the second state.

[0116] Example 3 like Figures 23 to 30 As shown, the extended lens assembly of Embodiment 3 is described. Figure 23 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly in the first state. Figure 24 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 25Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly in the first state. Figure 26 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly in the second state; Figure 27 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly of component 3 in its first state. Figure 28 Embodiment 3 provided in this application is shown. A schematic diagram of the extended lens assembly of 3 in the second state.

[0117] Example 3 includes 12 lenses. The effective focal lengths fq (at infinite object distance) and fw (at 1000mm object distance) of the optical system in Example 3 are both effective focal lengths when adapted to an imaging lens with a focal length of 22.48mm. The specific data for fq and fw in Example 3 are shown in the table below.

[0118] like Figures 23 to 28 As shown, the extended lens assembly according to an exemplary embodiment of this application includes a first lens barrel PM and a second lens barrel PN. The first lens barrel PM includes a first lens group G1 (participating in...). Figure 6 The second lens tube PN includes the second lens group G2 (participating in...). Figure 6 The first lens group G1 has positive optical power, and the second lens group G2 has positive optical power.

[0119] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a seventh lens E7.

[0120] 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 concave.

[0121] The second lens E2 has positive optical power, the object side S3 of the second lens E2 is convex, and the image side S4 of the second lens E2 is convex.

[0122] The third lens E3 has negative optical power, the object side S4 of the third lens E3 is concave, and the image side S5 of the third lens E3 is concave.

[0123] The fourth lens E4 has positive optical power, the object side S6 of the fourth lens E4 is convex, and the image side S7 of the fourth lens E4 is concave.

[0124] The fifth lens E5 has positive optical power, the object side S8 of the fifth lens E5 is convex, and the image side S9 of the fifth lens E5 is concave.

[0125] The sixth lens E6 has negative optical power. The object side S10 of the sixth lens E6 is convex, and the image side S11 of the sixth lens E6 is concave.

[0126] The seventh lens E7 has negative optical power. The object-side surface S12 of the seventh lens E7 is concave, and the image-side surface S13 of the seventh lens E7 is convex.

[0127] The second lens group G2 includes the eighth lens E8, the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0128] The eighth lens E8 has negative optical power, the object side S14 of the eighth lens E8 is concave, and the image side S15 of the eighth lens E8 is concave.

[0129] The ninth lens E9 has positive optical power, and the object-side surface S15 of the ninth lens E9 is convex, and the image-side surface S16 of the ninth lens E9 is convex.

[0130] The tenth lens E10 has negative optical power. The object side S17 of the tenth lens E10 is concave, and the image side S18 of the tenth lens E10 is concave.

[0131] 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.

[0132] 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.

[0133] An auxiliary element P0b is provided on the object side S1 of the first lens E1; a first spacer element P1 is provided on the image side S2 of the first lens E1; a third spacer element P3 is provided on the image side S5 of the third lens E3; a fifth spacer element P5 is provided on the image side S9 of the fifth lens E5; a sixth spacer element P6 is provided on the image side S11 of the sixth lens E6; an eighth spacer element P8 is provided on the image side S15 of the eighth lens E8; and a tenth spacer element P10 is provided on the image side S18 of the tenth lens E10.

[0134] In this embodiment, the second lens E2 and the third lens E3 are cemented together, the eighth lens E8 and the ninth lens E9 are cemented together, and the tenth lens E10 and the eleventh lens E11 are cemented together.

[0135] Figures 23 to 28 In the examples 3-1, 3-2 and 3-3, the extended lens assemblies have the same surface type, radius of curvature, thickness, refractive index and Abbe number.

[0136] The basic parameters of the extended lens assembly 10 in Embodiment 3 are shown in Table 5. The values ​​of D1, D2 and D3 in Table 1 are shown in Table 6.

[0137] Table 5

[0138] Table 6

[0139] Figure 29 A schematic diagram showing the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 3 in its first state is illustrated. Figure 29 As shown, the optical system given in Embodiment 3 can achieve good imaging quality in the first state.

[0140] Figure 30 A schematic diagram showing the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical system of Embodiment 3 in the second state is illustrated. Figure 30 As shown, the optical system given in Embodiment 3 can achieve good imaging quality in the second state.

[0141] The optical parameters of the extended lens assemblies in Examples 1, 2, and 3 are shown in Table 7 (unit: mm). The structural parameters of the extended lens assemblies in Examples 1, 2, and 3 are shown in Table 8 (unit: mm). The conditions satisfied by the extended lens assemblies in Examples 1, 2, and 3 are shown in Table 9. In Tables 7-9, 1-1, 1-2, and 1-3 correspond to Examples 1-1, 1-2, and 1-3 in Example 1, respectively; in Tables 7-9, 2-1, 2-2, and 2-3 correspond to Examples 2-1, 2-2, and 2-3 in Example 2, respectively; and in Tables 7-9, 3-1, 3-2, and 3-3 correspond to Examples 3-1, 3-2, and 3-3 in Example 3, respectively.

[0142] It should be noted that, for each embodiment in Table 8, the structural data in the first state and the second state are consistent. Similarly, for each embodiment in Table 9, the conditional values ​​in the first state and the second state are consistent.

[0143] Table 7

[0144] Table 8

[0145] Table 9

[0146] 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 extended lens assembly, wherein the extended lens assembly comprises, sequentially from the object side to the image side along the optical axis, a first lens barrel and a second lens barrel, characterized in that, The first lens barrel includes a first lens group, the first lens group having positive optical power, and the first lens group includes: A first lens with positive optical power, wherein the object side of the first lens is convex and the image side of the first lens is concave; A second lens with positive optical power, wherein the object-side surface of the second lens is convex and the image-side surface of the second lens is convex; A third lens with negative optical power, wherein the object-side surface of the third lens is concave and the image-side surface of the third lens is concave. A fourth lens with positive optical power, wherein the object-side surface of the fourth lens is convex and the image-side surface of the fourth lens is concave; 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 concave; A sixth lens with negative optical power, wherein the object-side surface of the sixth lens is convex and the image-side surface of the sixth lens is concave; 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 convex; The second lens barrel contains a second lens group, the second lens group having positive optical power, and the second lens group includes: An eighth lens with negative optical power, wherein the object-side surface of the eighth lens is concave and the image-side surface of the eighth lens is concave. A ninth lens with positive optical power, wherein the object-side surface of the ninth lens is convex and the image-side surface of the ninth lens is convex. A tenth lens with negative optical power, wherein the object side of the tenth lens is concave and the image side of the tenth lens is concave. An eleventh lens with positive optical power, wherein the object-side surface of the eleventh lens is convex and 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; The first lens to the twelfth lens are arranged sequentially from the object side to the image side, and a tenth spacer element is provided on the image side side of the tenth lens; The second lens barrel can move along the optical axis to achieve zoom; and satisfies: 2.00<(CT10+CT11+CT12) / CP10<2.50; 3.40<CT11 / (D10s-d10s)<6.80; CT10 is the center thickness of the tenth lens, CT11 is the center thickness of the eleventh lens, CT12 is the center thickness of the twelfth lens, CP10 is the maximum thickness of the tenth spacer element along the optical axis, D10s is the outer diameter of the side surface of the tenth spacer element, and d10s is the inner diameter of the side surface of the tenth spacer element.

2. The extended lens assembly according to claim 1, characterized in that, The extended lens assembly satisfies: 11.11 ≤ L² / ΔT ≤ 13.

95. Wherein, L2 is the maximum thickness of the second lens barrel along the optical axis, and ΔT is the distance the second lens barrel moves along the optical axis when the extended lens assembly changes from an infinite object distance state to a 1000mm object distance state.

3. The extended lens assembly according to claim 1, characterized in that, A first spacer element is provided on the image-side surface of the first lens, and the extended lens assembly satisfies: 5.05 < d1s / T12 < 6.

10. Wherein, d1s is the inner diameter of the object side of the first spacer element, and T12 is the air gap between the first lens and the second lens on the optical axis.

4. The extended lens assembly according to claim 1, characterized in that, A first spacer element is provided on the image-side surface of the first lens, and the extended lens assembly satisfies: 3.00≤CP1 / (D1m-d1m)≤7.

15. Wherein, CP1 is the maximum thickness of the first spacer element along the optical axis, d1m is the inner diameter of the image-side surface of the first spacer element, and D1m is the outer diameter of the image-side surface of the first spacer element.

5. The extended lens assembly according to claim 1, characterized in that, A sixth spacer element is provided on the image-side surface of the sixth lens, and the extended lens assembly satisfies: 1.60 < LG1 / (D6s + D6m) < 2.

15. Wherein, LG1 is the axial distance from the object side of the first lens to the image side of the seventh lens, D6s is the outer diameter of the object side of the sixth spacer element, and D6m is the outer diameter of the image side of the sixth spacer element.

6. The extended lens assembly according to claim 1, characterized in that, A third spacer element is provided on the image-side surface of the third lens, and the extended lens assembly satisfies: -11.40≤F23 / (D3s-d3s)≤-5.

65. Wherein, F23 is the combined focal length of the second lens and the third lens, D3s is the outer diameter of the object side of the third spacer element, and d3s is the inner diameter of the object side of the third spacer element.

7. The extended lens assembly according to claim 1, characterized in that, A lens barrel auxiliary element is provided on the object side of the first lens, and the extended lens assembly satisfies: 1.05≤F1234 / (d0bs+D0bs)≤1.

99. Wherein, F1234 is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, d0bs is the inner diameter of the object side surface of the lens barrel auxiliary element, and D0bs is the outer diameter of the object side surface of the lens barrel auxiliary element.

8. The extended lens assembly according to claim 1, characterized in that, A fifth spacer element is provided on the image-side surface of the fifth lens; a sixth spacer element is provided on the image-side surface of the sixth lens. The extended lens assembly satisfies: 1.81≤(CT6+T67) / (CP5+CP6)≤2.

50. Wherein, CT6 is the center thickness of the sixth lens, T67 is the air gap between the sixth lens and the seventh lens on the optical axis, CP5 is the maximum thickness of the fifth spacer element along the optical axis, and CP6 is the maximum thickness of the sixth spacer element along the optical axis.

9. The extended lens assembly according to claim 1, characterized in that, The extended lens assembly satisfies: 1.90 ≤ L1 / (∑CTG1+∑CTG2) < 2.

45. Wherein, L1 is the maximum thickness of the first lens barrel along the optical axis, ∑CTG1 is the sum of the center thicknesses of all lenses from the first lens to the seventh lens, and ∑CTG2 is the sum of the center thicknesses of all lenses from the eighth lens to the twelfth lens.

10. The extended lens assembly according to claim 1, characterized in that, An eighth spacer element is provided on the image-side surface of the eighth lens, and the extended lens assembly satisfies: 1.85 < LG² / d⁸s < 3.

50. Wherein, LG2 is the axial distance from the object side of the eighth lens to the image side of the twelfth lens, and d8s is the inner diameter of the object side of the eighth spacer element.

11. The extended lens assembly according to claim 1, characterized in that, A fifth spacer element is provided on the image-side surface of the fifth lens; a sixth spacer element is provided on the image-side surface of the sixth lens. The extended lens assembly satisfies: 1.15 < (d5s + d5m) / (d6s + d6m) < 1.

80. Wherein, d5s is the inner diameter of the object side of the fifth spacer element, d5m is the inner diameter of the image side of the fifth spacer element, d6s is the inner diameter of the object side of the sixth spacer element, and d6m is the inner diameter of the image side of the sixth spacer element.

12. The extended lens assembly according to claim 1, characterized in that, The extended lens assembly satisfies: 5.90 < F101112 / CP10 < 8.

15. Wherein, F101112 is the combined focal length of the tenth lens, the eleventh lens and the twelfth lens, and CP10 is the maximum thickness of the tenth spacer element along the optical axis.

13. The extended lens assembly according to claim 1, characterized in that, An auxiliary lens element is provided on the object side of the first lens, and the extended lens assembly satisfies: 1.55 < CT1 / CP0b < 2.

85. Wherein, CT1 is the center thickness of the first lens, and CP0b is the maximum thickness of the lens barrel auxiliary element along the optical axis.

14. The extended lens assembly according to claim 1, characterized in that, A first spacer element is provided on the image-side surface of the first lens, and a fifth spacer element is provided on the image-side surface of the fifth lens. The extended lens assembly satisfies: 1.15 < FG1 / (D1s+D5s) < 1.

55. Wherein, FG1 is the combined focal length of the first lens group, D1s is the outer diameter of the object side of the first spacer element, and D5s is the outer diameter of the object side of the fifth spacer element.

15. An optical system comprising: The extended lens assembly according to any one of claims 1-14; An imaging lens is located on the image side of the twelfth lens; as well as Imaging plane, The beam emitted from the extended lens assembly enters the imaging lens to form an image on the imaging surface using the imaging lens. An eighth spacer element is provided on the image-side surface of the eighth lens, and the extended lens assembly satisfies: 1.25 < FG2 / d8m < 1.

95. Wherein, FG2 is the combined focal length of the second lens group, and d8m is the inner diameter of the image side of the eighth spacer element.

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