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 sixth lens. The second lens barrel contains a second lens group. The second lens group comprises a seventh lens to a twelfth lens. The second lens barrel is movable along an optical axis to realize zooming. The following conditions are met: 3.15 < L1 / L2 < 3.65; 4.15 < CP4 / (D4s-d4s) < 8.45; L1 is the maximum thickness of the first lens barrel along the optical axis direction, L2 is the maximum thickness of the second lens barrel along the optical axis direction, CP4 is the maximum thickness of a fourth spacer element along the optical axis direction, D4s is the outer diameter of the object side surface of the fourth spacer element, and d4s is the inner diameter of the object side surface of the fourth spacer element. The expansion lens assembly can block the scattered stray light generated on the image side of the fourth lens from propagating to the rear end optical path, and inhibit the stray light from reaching the imaging surface to form a stray light spot.

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 continuous development of imaging technology in electronic devices, extended lenses are widely used to achieve functions such as field of view expansion and zoom imaging. Existing extended lens assemblies mostly use multiple lens groups with a movable lens barrel to achieve zoom. To achieve miniaturization, the structural dimensions of the lens barrel, spacers, and other components are constantly being compressed. However, in the optical structure coupling design, focusing only on the optical power and surface shape optimization of the lenses while ignoring the influence of the structural parameters of the lens barrel and spacers on the optical path can easily lead to problems such as insufficient light-blocking ability of the spacers and poor assembly rigidity. This can result in defects such as stray light, ghosting, and lens misalignment, causing a decline in image quality and making it difficult to simultaneously achieve miniaturization, zoom performance, and mass production assembly yield. Summary of the Invention

[0003] 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 which is convex; a second lens having positive optical power, the object side of which is convex and the image side of which is convex; and a third lens having negative optical power, the object side of which is concave and the image side of which is concave. The second lens barrel contains a second lens group with 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 convex; 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 concave and the image-side surface of the sixth lens is concave; the second lens group includes a second lens group with positive optical power, the second lens group including: a seventh lens with positive optical power, wherein the object-side surface of the seventh lens is concave and the image-side surface of the seventh lens is concave. The image-side surface of the lens is convex; the eighth lens has negative optical power, the object-side surface of the eighth lens is concave, and the image-side surface of the eighth lens is concave; the ninth lens has positive optical power, the object-side surface of the ninth lens is convex, and the image-side surface of the ninth lens is convex; the tenth lens has negative optical power, the object-side surface of the tenth lens is concave, and the image-side surface of the tenth lens is concave; the eleventh lens has positive optical power, the image-side surface of the eleventh lens is convex; the twelfth lens has positive optical power, the object-side surface of the twelfth lens is concave, and the image-side surface of the twelfth lens is concave. The first lens is convex; a fourth spacer element is provided on the image-side surface of the fourth lens; the second lens barrel can move along the optical axis to achieve zoom; and satisfies: 3.15 < L1 / L2 < 3.65; 4.15 < CP4 / (D4s-d4s) < 8.45; L1 is the maximum thickness of the first lens barrel along the optical axis, L2 is the maximum thickness of the second lens barrel along the optical axis, CP4 is the maximum thickness of the fourth spacer element along the optical axis, D4s is the outer diameter of the object-side surface of the fourth spacer element, and d4s is the inner diameter of the object-side surface of the fourth spacer element.

[0004] According to an embodiment of this application, a first spacer element is provided on the image-side surface of the first lens; the extended lens assembly satisfies: 5.75≤FG1 / CP1≤7.10, where FG1 is the combined focal length of the first lens group and CP1 is the maximum thickness of the first spacer element along the optical axis.

[0005] 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: -3.70 < F23 / d3s < -3.25, where F23 is the combined focal length of the second lens and the third lens, and d3s is the inner diameter of the object-side surface of the third spacer element.

[0006] According to an embodiment of this application, a seventh spacer element is provided on the image side of the seventh lens, and the extended lens assembly satisfies: 1.65 < d7s / CT7 < 2.55, where d7s is the inner diameter of the object side of the seventh spacer element, and CT7 is the center thickness of the seventh lens.

[0007] According to an embodiment of this application, a tenth spacer element is provided on the image-side surface of the tenth lens, and the extended lens assembly satisfies: 1.55 < LG2 / d10s < 2.05, where LG2 is the axial distance from the object-side surface of the seventh lens to the image-side surface of the twelfth lens, and d10s is the inner diameter of the object-side surface of the tenth spacer element.

[0008] 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: 7.40≤d0bs / CT1≤8.18, where d0bs is the inner diameter of the object side of the lens barrel auxiliary element, and CT1 is the center thickness of the first lens.

[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: 2.20 < (D3s - d3s) / (D3m - d3m) < 3.85, where D3s is the outer diameter of the object-side surface of the third spacer element, d3s is the inner diameter of the object-side surface of the third spacer element, D3m is the outer diameter of the image-side surface of the third spacer element, and d3m is the inner diameter of the image-side surface of the third spacer element.

[0010] According to an embodiment of this application, an eighth spacer element is provided on the image-side surface of the eighth lens; the extended lens assembly satisfies: 1.10 < (d8s + d8m) / F789 < 1.70, where d8s is the inner diameter of the object-side surface of the eighth spacer element, d8m is the inner diameter of the image-side surface of the eighth spacer element, and F789 is the combined focal length of the seventh lens, the eighth lens, and the ninth lens.

[0011] 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: 9.55 < (R6 + R7) / CP3 < 13.00, where R6 is the radius of curvature of the image-side surface of the third lens, R7 is the radius of curvature of the object-side surface of the fourth lens, and CP3 is the maximum thickness of the third spacer element along the optical axis.

[0012] According to an embodiment of this application, a twelfth spacer element is provided on the image-side surface of the twelfth lens, and the extended lens assembly satisfies: 8.80 < d12m / ΔT < 11.00, where d12m is the inner diameter of the image-side surface of the twelfth spacer element, 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.

[0013] 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: 26.98≤F1234 / CP0b≤31.17, where F1234 is the combined focal length of the first lens, the second lens, the third lens, and the fourth lens, and CP0b is the maximum thickness of the lens barrel auxiliary element along the optical axis.

[0014] According to an embodiment of this application, a twelfth spacer element is provided on the image-side surface of the twelfth lens, and the extended lens assembly satisfies: 4.50 < D12m / CT12 < 5.65, where D12m is the outer diameter of the image-side surface of the twelfth spacer element, and CT12 is the center thickness of the twelfth lens.

[0015] 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: 2.40≤CT2 / (D1m-d1m)≤5.80, where CT2 is the center thickness of the second lens, D1m is the outer diameter of the image-side surface of the first spacer element, and d1m is the inner diameter of the image-side surface of the first spacer element.

[0016] According to an embodiment of this application, a tenth spacer element is provided on the image-side surface of the tenth lens, and the extended lens assembly satisfies: 0.85 < f11 / d10m < 1.30, where f11 is the effective focal length of the eleventh lens and d10m is the inner diameter of the image-side surface of the tenth spacer element.

[0017] Another aspect of this application provides an optical system comprising: an extended lens assembly as described in any one 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, a twelfth spacer element is disposed on the image side of the twelfth lens, and the extended lens assembly satisfies: 6.70 < FG2 / CP12 < 13.70, where FG2 is the combined focal length of the second lens group, and CP12 is the maximum thickness of the twelfth spacer element along the optical axis.

[0018] According to the technical solution of this application embodiment, under the premise of 3.15 < L1 / L2 < 3.65, stray light is easily generated on the image side of the fourth lens in the extended lens assembly. Therefore, this application, by constraining the range of 4.15 < CP4 / (D4s-d4s) < 8.45, reasonably designs the thickness and inner and outer diameters of the fourth spacer element, which can effectively block the propagation of scattered stray light generated on the image side of the fourth lens to the rear optical path, while suppressing secondary reflection on the inner wall of the fourth spacer element, and avoiding stray light reaching the imaging surface to form stray light spots. When the lower limit of CP4 / (D4s-d4s) is exceeded, the axial thickness of the fourth spacer element is insufficient, the light-blocking height is insufficient, and some scattered stray light directly crosses the spacer ring and enters the rear optical path, and obvious stray light spots can be observed on the imaging surface; when the upper limit of CP4 / (D4s-d4s) is exceeded, the radial ring width of the fourth spacer element is too small, the inner wall reflection area increases, secondary reflection stray light is generated on the inner wall of the fourth spacer element, and diffuse stray light spots appear on the imaging surface. Attached Figure Description

[0019] 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: Figure 1 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when L1 / L2=3.30 and CP4 / (D4s-d4s)=3.70 is satisfied; Figure 2 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when L1 / L2=3.30 and CP4 / (D4s-d4s)=6.10 is satisfied; Figure 3 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when L1 / L2=3.30 and CP4 / (D4s-d4s)=8.70 is satisfied; 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 30 A 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

[0020] 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.

[0021] 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.

[0022] 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 drawn strictly to scale.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The features, principles and other aspects of this application are described in detail below.

[0028] 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; 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; and 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. The second lens barrel contains a second lens group with positive optical power, the object-side surface of the fourth lens being convex and the image-side surface of the fourth lens being convex; a fifth lens with positive optical power, the object-side surface of the fifth lens being convex and the image-side surface of the fifth lens being concave; a sixth lens with negative optical power, the object-side surface of the sixth lens being concave and the image-side surface of the sixth lens being concave; the second lens group includes a second lens group with positive optical power, the second lens group including: a seventh lens with positive optical power, the object-side surface of the seventh lens being concave and the image-side surface of the seventh lens being concave. The image surface of the eighth lens is convex; the object-side surface of the eighth lens is concave, and 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 image-side surface of the eleventh lens is convex, and the image-side surface of the eleventh lens is convex; the image-side surface of the twelfth lens is concave, and the image-side surface of the twelfth lens is convex. The first lens is convex; a fourth spacer element is provided on the image side of the fourth lens; the second lens barrel can move along the optical axis to achieve zoom; and satisfies: 3.15 < L1 / L2 < 3.65; 4.15 < CP4 / (D4s-d4s) < 8.45; L1 is the maximum thickness of the first lens barrel along the optical axis, L2 is the maximum thickness of the second lens barrel along the optical axis, CP4 is the maximum thickness of the fourth spacer element along the optical axis, D4s is the outer diameter of the object side of the fourth spacer element, and d4s is the inner diameter of the object side of the fourth spacer element.

[0029] Figure 1 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when L1 / L2=3.30 and CP4 / (D4s-d4s)=3.70 is satisfied; Figure 2 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when L1 / L2=3.30 and CP4 / (D4s-d4s)=6.10 is satisfied; Figure 3 The stray light pattern of the extended lens assembly provided in at least one embodiment of this application is shown when L1 / L2=3.30 and CP4 / (D4s-d4s)=8.70 is satisfied.

[0030] like Figure 1As shown, the stray light pattern was obtained with L1 / L2=3.30 and CP4 / (D4s-d4s)=3.70. Figure 1 It presents a semi-circular diffused light spot, with the light energy diffused into the lower half of the region.

[0031] like Figure 2 As shown, the spot pattern was obtained with L1 / L2=3.30 and CP4 / (D4s-d4s)=6.10. Figure 2 The mid-light spots are almost invisible, and the overall image is clean.

[0032] like Figure 3 As shown, the spot pattern was obtained with L1 / L2=3.30 and CP4 / (D4s-d4s)=8.70. Figure 3 The light spots are scattered, forming multiple clusters of discrete light spots, with no obvious concentrated main light spot. Multiple small light spots are scattered, and the light spot clusters have lateral tails, resulting in a large diffusion range.

[0033] Therefore, under the condition that 3.15 < L1 / L2 < 3.65, stray light is easily generated on the image side of the fourth lens when extending the lens assembly. Therefore, this application, by constraining the range of 4.15 < CP4 / (D4s-d4s) < 8.45, reasonably designs the thickness and inner and outer diameters of the fourth spacer element, which can effectively block the propagation of scattered stray light generated on the image side of the fourth lens to the rear optical path, while suppressing secondary reflections on the inner wall of the fourth spacer element, and preventing stray light from reaching the imaging surface and forming stray light spots. When the lower limit of CP4 / (D4s-d4s) is exceeded by 4.15, the axial thickness of the fourth spacer element is insufficient, the light-blocking height is insufficient, and some scattered stray light directly crosses the spacer ring and enters the rear optical path, and obvious stray light spots can be observed on the imaging surface. When the upper limit of CP4 / (D4s-d4s) is exceeded by 8.45, the radial ring width of the fourth spacer element is too small, the inner wall reflection area increases, secondary reflection stray light is generated on the inner wall of the fourth spacer element, and diffuse stray light spots appear on the imaging surface.

[0034] In an exemplary embodiment, a first spacer element is provided on the image-side surface of the first lens; the extended lens assembly satisfies: 5.75 ≤ FG1 / CP1 ≤ 7.10, where FG1 is the combined focal length of the first lens group and CP1 is the maximum thickness of the first spacer element along the optical axis. This embodiment reasonably controls the range of this conditional expression to ensure the structural rigidity and assembly coaxiality of the first spacer element, while taking into account both lens miniaturization and imaging consistency in mass production. When FG1 / CP1 is too small, the thickness of the first spacer element is too large, increasing the axial dimension of the lens barrel, interfering with the light incident conditions, and exacerbating spherical aberration and coma; when FG1 / CP1 is too large, the thickness of the first spacer element is insufficient, making it prone to deformation and causing lens eccentricity and tilting.

[0035] 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: -3.70 < F23 / d3s < -3.25, where F23 is the combined focal length of the second and third lenses, and d3s is the inner diameter of the object-side surface of the third spacer element. This embodiment reasonably controls this conditional range, ensuring light transmission and suppressing vignetting while constraining the light transmission aperture of the third spacer element, blocking stray light reflection, taking into account radial assembly positioning accuracy, and improving the imaging quality of the entire field of view. When F23 / d3s is too small, the effective light transmission aperture is easily blocked by the third spacer element, reducing light transmission and inducing edge field of view vignetting; when F23 / d3s is too large, stray light is easily reflected into the optical path through the inner wall of the third spacer element, exacerbating ghost glare, and also leading to insufficient radial positioning margin of the lens.

[0036] In an exemplary embodiment, a seventh spacer element is provided on the image-side surface of the seventh lens, and the extended lens assembly satisfies: 1.65 < d7s / CT7 < 2.55, where d7s is the inner diameter of the object-side surface of the seventh spacer element, and CT7 is the center thickness of the seventh lens. This embodiment reasonably controls this conditional range, balancing light transmission capability and stray light suppression effect, ensuring the structural strength of the seventh lens, improving the assembly stability of the movable second lens barrel, and optimizing the imaging quality throughout the zoom range. When d7s / CT7 is too small, the inner diameter of the seventh spacer element is too small, and light blocking can easily cause vignetting at the edge of the field of view; when d7s / CT7 is too large, the inner diameter of the seventh spacer element is too large, and stray light can easily be reflected through the inner wall of the seventh spacer element to form ghost images, and the center thickness of the lens is relatively thin, resulting in a decrease in the lens's resistance to deformation.

[0037] In an exemplary embodiment, a tenth spacer element is provided on the image-side surface of the tenth lens, and the extended lens assembly satisfies: 1.55 < LG2 / d10s < 2.05, where LG2 is the axial distance from the object-side surface of the seventh lens to the image-side surface of the twelfth lens, and d10s is the inner diameter of the object-side surface of the tenth spacer element. This embodiment reasonably controls this conditional range, ensuring the light transmission of the second lens group while suppressing stray light, optimizing the axial volume of the second lens barrel and the zoom stroke, and ensuring the stability of full-field imaging during zooming. When LG2 / d10s is too small, the light-blocking constraint of the tenth spacer element is insufficient, and stray light is easily reflected into the optical path, causing ghosting flare; when LG2 / d10s is too large, it is easy to cause edge vignetting and also increases the zoom stroke of the second lens barrel, which is not conducive to the miniaturization of the whole device.

[0038] 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: 7.40≤d0bs / CT1≤8.18, where d0bs is the inner diameter of the object side of the lens barrel auxiliary element and CT1 is the center thickness of the first lens. This embodiment reasonably controls this conditional range, balancing front-end light transmission capability and stray light suppression, ensuring the structural strength of the first lens, improving the lens front-end's resistance to external force disturbances, and ensuring the overall imaging stability. When d0bs / CT1 is too small, the inner diameter of the lens barrel auxiliary element is too small, which can easily cause vignetting at the edge of the field of view; when d0bs / CT1 is too large, the inner diameter of the lens barrel auxiliary element is too large, and stray light can easily enter the optical path through reflection from the inner wall. At the same time, the center thickness of the first lens is too thin, resulting in decreased impact and deformation resistance.

[0039] 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: 2.20 < (D3s - d3s) / (D3m - d3m) < 3.85, where D3s is the outer diameter of the object-side surface of the third spacer element, d3s is the inner diameter of the object-side surface of the third spacer element, D3m is the outer diameter of the image-side surface of the third spacer element, and d3m is the inner diameter of the image-side surface of the third spacer element. This embodiment reasonably controls the range of this conditional expression, so that the two sides of the third spacer element obtain reasonable support ring widths, ensuring positioning stiffness, improving lens coaxiality, suppressing stray light from the inner wall, and improving batch assembly yield. When (D3s - d3s) / (D3m - d3m) is too small, the object-side ring width is insufficient and the rigidity is poor, making it easy to deform under assembly stress and causing lens eccentricity; when (D3s - d3s) / (D3m - d3m) is too large, the object-side ring width is too large, occupying radial space and increasing the risk of stray light caused by inner wall reflection.

[0040] In an exemplary embodiment, an eighth spacer element is provided on the image-side surface of the eighth lens; the extended lens assembly satisfies: 1.10 < (d8s + d8m) / F789 < 1.70, where d8s is the inner diameter of the object-side surface of the eighth spacer element, d8m is the inner diameter of the image-side surface of the eighth spacer element, and F789 is the combined focal length of the seventh, eighth, and ninth lenses. This embodiment reasonably controls the range of this conditional expression, balances the light-gathering aperture and stray light suppression effect, stabilizes the light-gathering characteristics of the lens group, and ensures the full field-of-view imaging quality during the zoom movement of the second lens barrel. When the ratio is too small, the overall light-gathering aperture of the eighth spacer element is too small, causing vignetting at the edge of the field of view, and also changes the light propagation path within the group, degrading aberrations in the zoom range; when the ratio is too large, the light-gathering aperture is too large, and stray light is easily reflected through the inner wall of the spacer ring to form ghost images.

[0041] 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: 9.55 < (R6 + R7) / CP3 < 13.00, where R6 is the radius of curvature of the image-side surface of the third lens, R7 is the radius of curvature of the object-side surface of the fourth lens, and CP3 is the maximum thickness of the third spacer element along the optical axis. This embodiment reasonably controls the range of this conditional expression, taking into account both the structural stiffness of the third spacer element and the curvature of the lens, effectively correcting spherical aberration and field curvature in this region, ensuring coaxial assembly accuracy, and improving the consistency of imaging across the entire field of view. When the ratio is too small, the thickness of the third spacer element is too large, the air gap within the assembly is excessively amplified, the distortion of the incident angle of light is aggravated, and spherical aberration and field curvature deteriorate; when the ratio is too large, the thickness of the third spacer element is insufficient, its stiffness decreases and it is prone to deformation, and at the same time, the mismatch between the curved surfaces of the two lenses will aggravate local astigmatism.

[0042] In an exemplary embodiment, a twelfth spacer element is provided on the image-side surface of the twelfth lens, and the extended lens assembly satisfies: 8.80 < d12m / ΔT < 11.00, where d12m is the inner diameter of the image-side surface of the twelfth spacer element, and ΔT is the distance the second lens barrel moves along the optical axis when the extended lens assembly changes from an infinity object distance to a 1000mm object distance. This embodiment reasonably controls this conditional range, balancing light transmission performance and focusing compensation capability, optimizing the movement stroke of the second lens barrel, ensuring imaging quality from infinity to a 1000mm object distance, while reducing the space occupied by the mechanism. When d12m / ΔT is too small, the focusing stroke is too large, which increases the space requirement for the mechanism's movement, is not conducive to lens miniaturization, and is also prone to vignetting during movement; when d12m / ΔT is too large, the focusing stroke is too small, the focusing compensation capability is insufficient, and it is difficult to effectively correct near-object distance imaging aberrations.

[0043] 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: 26.98 ≤ F1234 / CP0b ≤ 31.17, where F1234 is the combined focal length of the first, second, third, and fourth lenses, and CP0b is the maximum thickness of the lens barrel auxiliary element along the optical axis. This embodiment reasonably controls this conditional range, balancing the protective rigidity of the front-end structure with the compactness of the lens, stabilizing the optical focal length of the front lens group, ensuring the incident light conditions, and improving the overall assembly reliability and imaging stability. When F1234 / CP0b is too small, the thickness of the lens barrel auxiliary element is too large, increasing the axial dimension of the lens front end, changing the incident light path, and easily introducing spherical aberration; when F1234 / CP0b is too large, the thickness of the lens barrel auxiliary element is too thin, the structural strength is insufficient, and the impact resistance and limiting protection capabilities decrease.

[0044] In an exemplary embodiment, a twelfth spacer element is provided on the image-side surface of the twelfth lens, and the extended lens assembly satisfies: 4.50 < D12m / CT12 < 5.65, where D12m is the outer diameter of the image-side surface of the twelfth spacer element, and CT12 is the center thickness of the twelfth lens. This embodiment reasonably controls the range of this conditional expression to ensure the effective support area of ​​the twelfth spacer element, enhance the positioning reliability of the twelfth lens, adapt to the zoom movement conditions of the second lens barrel, suppress aberrations introduced by assembly, and improve the consistency of batch imaging. When D12m / CT12 is too small, the outer diameter of the twelfth spacer element is too small, the radial support contact area is insufficient, and the lens positioning is unstable and prone to eccentricity; when D12m / CT12 is too large, the center thickness of the lens is relatively thin, the lens's resistance to deformation is poor, and it is easily affected by assembly stress.

[0045] 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: 2.40≤CT2 / (D1m-d1m)≤5.80, where CT2 is the center thickness of the second lens, D1m is the outer diameter of the image-side surface of the first spacer element, and d1m is the inner diameter of the image-side surface of the first spacer element. This embodiment reasonably controls the range of this condition, taking into account both the structural strength of the second lens itself and the radial support stiffness of the first spacer element, ensuring the coaxial positioning accuracy of the lens, reducing aberrations introduced by assembly, and improving the mass production yield. When CT2 / (D1m-d1m) is too small, the center thickness of the second lens is relatively thin, and the lens is easily deformed by assembly stress; when CT2 / (D1m-d1m) is too large, the ring width of the first spacer element is insufficient, the support contact area is small, the positioning stability is poor, and lens eccentricity is easily generated.

[0046] In an exemplary embodiment, a tenth spacer element is provided on the image-side surface of the tenth lens, and the extended lens assembly satisfies: 0.85 < f11 / d10m < 1.30, where f11 is the effective focal length of the eleventh lens, and d10m is the inner diameter of the image-side surface of the tenth spacer element. This embodiment reasonably controls this conditional range to adapt to the beam converging capability of the eleventh lens, balance the amount of light transmitted and the suppression of stray light, and ensure the full field-of-view imaging effect during the zooming process of the second lens barrel. When f11 / d10m is too small, the inner diameter of the tenth spacer element is too large, and stray light is easily reflected by the inner wall to form ghosting. At the same time, the beam width exceeds the lens adaptation range, degrading the field curvature. When f11 / d10m is too large, the inner diameter of the tenth spacer element is too small, which easily causes vignetting at the edge of the field of view and aggravates aberrations during the zooming process.

[0047] 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 from the extended lens assembly enters the imaging lens to image on the imaging surface. A twelfth spacer element is disposed on the image side of the twelfth lens, and the extended lens assembly satisfies: 6.70 < FG2 / CP12 < 13.70, where FG2 is the combined focal length of the second lens group, and CP12 is the maximum thickness of the twelfth spacer element along the optical axis. By reasonably controlling this conditional range, the mechanical structural stability of the lenses within the second lens group and the twelfth spacer element is ensured during the movement stroke of the second lens barrel.

[0048] Figure 4 and Figure 5 A schematic diagram showing the dimensions of an extended lens assembly of this application is provided.

[0049] Figure 4 The 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 inner diameter d0bs of the object side of the lens barrel auxiliary 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 outer diameter D4s of the object side of the fourth spacer element, the inner diameter d4s of the object side of the fourth spacer element, the inner diameter d8s of the object side of the eighth spacer element, the inner diameter d7s of the object side of the seventh 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.

[0050] Figure 5 The diagram clearly shows the outer diameter D1m of the image-side surface of the first spacer element, the inner diameter d1m of the image-side surface of the first spacer element, the outer diameter D3m of the image-side surface of the third spacer element, the inner diameter d3m of the image-side surface of the third spacer element, the inner diameter d8m of the image-side surface of the eighth spacer element, the inner diameter d10m of the image-side surface of the tenth spacer element, the inner diameter d12m of the image-side surface of the twelfth spacer element, the outer diameter D12m of the image-side surface of the twelfth 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 CP3 of the third spacer element along the optical axis, the maximum thickness CP4 of the fourth spacer element along the optical axis, and the maximum thickness CP12 of the twelfth spacer element along the optical axis, etc., to provide a clear and intuitive understanding of the meaning of these parameters.

[0051] 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.

[0052] Figure 6 A schematic diagram of the overall architecture of an optical system provided in this application is shown.

[0053] 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.

[0054] 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.

[0055] 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, and a sixth lens E6. The first lens E1 has positive optical power, and its object-side surface is convex. The second lens E2 has positive optical power, and both its object-side and image-side surfaces are convex. The third lens E3 has negative optical power, and both its object-side and image-side surfaces are concave. The fourth lens E4 has positive optical power, and both its object-side and image-side surfaces are convex. The fifth lens E5 has positive optical power, and both its object-side and image-side surfaces are convex. The sixth lens E6 has negative optical power, and both its object-side and image-side surfaces are concave.

[0056] The second lens group G2 includes a seventh lens E7, an eighth lens E8, a ninth lens E9, a tenth lens E10, an eleventh lens E11, and a twelfth lens E12. The seventh lens E7 has positive optical power, a concave object-side surface, and a convex image-side surface. The eighth lens E8 has negative optical power, a concave object-side surface, and a concave image-side surface; the ninth lens E9 has positive optical power, a convex object-side surface, and a convex image-side surface; the tenth lens E10 has negative optical power, a concave object-side surface, and a concave image-side surface; the eleventh lens E11 has positive optical power, a convex image-side surface; and the twelfth lens E12 has positive optical power, a concave object-side surface, and a convex image-side surface.

[0057] A fourth spacer element is provided on the image side of the fourth lens; the second lens barrel can move along the optical axis to achieve zoom; and satisfies: 3.15 < L1 / L2 < 3.65; 4.15 < CP4 / (D4s-d4s) < 8.45; L1 is the maximum thickness of the first lens barrel along the optical axis, L2 is the maximum thickness of the second lens barrel along the optical axis, CP4 is the maximum thickness of the fourth spacer element along the optical axis, D4s is the outer diameter of the object side of the fourth spacer element, and d4s is the inner diameter of the object side of the fourth spacer element.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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, and a sixth lens E6.

[0067] The first lens E1 has positive optical power, the object side S1 of the first lens E1 is convex, and the image side S2 of the first lens E1 is convex.

[0068] 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.

[0069] 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.

[0070] 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 convex.

[0071] 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.

[0072] The sixth lens E6 has negative optical power. The object side S10 of the sixth lens E6 is concave, and the image side S11 of the sixth lens E6 is concave.

[0073] The second lens group G2 includes the seventh lens E7, the eighth lens E8, the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0074] The seventh lens E7 has positive 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] The eleventh lens E11 has positive optical power. The object-side surface S20 of the eleventh lens E11 is concave, and the image-side surface S21 of the eleventh lens E11 is convex.

[0079] The twelfth lens E12 has positive optical power. The object side surface S22 of the twelfth lens E12 is concave, and the image side surface S23 of the twelfth lens E12 is convex.

[0080] 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 fourth spacer element P4 is provided on the image side S7 of the fourth lens E4; a seventh spacer element P7 is provided on the image side S13 of the seventh lens E7; an eighth spacer element P8 is provided on the image side S15 of the eighth lens E8; a tenth spacer element P10 is provided on the image side S19 of the tenth lens E10; and a twelfth spacer element P12 is provided on the image side S23 of the twelfth lens E12.

[0081] In this embodiment, the second lens E2 and the third lens E3 are cemented together.

[0082] 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.

[0083] 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.

[0084] Table 1

[0085] Table 2

[0086] 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 13 As shown, the optical system given in Example 1 can achieve good imaging quality in the first state.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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, and a sixth lens E6.

[0092] The first lens E1 has positive optical power, the object side S1 of the first lens E1 is convex, and the image side S2 of the first lens E1 is convex.

[0093] 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.

[0094] 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.

[0095] 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 convex.

[0096] 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.

[0097] The sixth lens E6 has negative optical power. The object side S10 of the sixth lens E6 is concave, and the image side S11 of the sixth lens E6 is concave.

[0098] The second lens group G2 includes the seventh lens E7, the eighth lens E8, the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0099] The seventh lens E7 has positive 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] The twelfth lens E12 has positive optical power. The object side S21 of the twelfth lens E12 is concave, and the image side S22 of the twelfth lens E12 is convex.

[0105] 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 fourth spacer element P4 is provided on the image side S7 of the fourth lens E4; a seventh spacer element P7 is provided on the image side S13 of the seventh lens E7; an eighth spacer element P8 is provided on the image side S15 of the eighth lens E8; a tenth spacer element P10 is provided on the image side S19 of the tenth lens E10; and a twelfth spacer element P12 is provided on the image side S22 of the twelfth lens E12.

[0106] 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.

[0107] 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.

[0108] 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 3 are shown in Table 4.

[0109] Table 3

[0110] Table 4

[0111] 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.

[0112] 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.

[0113] 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 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 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.

[0114] 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.

[0115] 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.

[0116] 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, and a sixth lens E6.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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 convex.

[0121] 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.

[0122] The sixth lens E6 has negative optical power. The object side S10 of the sixth lens E6 is concave, and the image side S11 of the sixth lens E6 is concave.

[0123] The second lens group G2 includes the seventh lens E7, the eighth lens E8, the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0124] The seventh lens E7 has positive 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] The twelfth lens E12 has positive optical power. The object-side surface S20 of the twelfth lens E12 is concave, and the image-side surface S21 of the twelfth lens E12 is convex.

[0130] 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 fourth spacer element P4 is provided on the image side S7 of the fourth lens E4; a seventh spacer element P7 is provided on the image side S13 of the seventh lens E7; an eighth spacer element P8 is provided on the image side S15 of the eighth lens E8; a tenth spacer element P10 is provided on the image side S18 of the tenth lens E10; and a twelfth spacer element P12 is provided on the image side S21 of the twelfth lens E12.

[0131] 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.

[0132] 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.

[0133] 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 5 are shown in Table 6.

[0134] Table 5

[0135] Table 6

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] Table 7

[0141] Table 8

[0142] Table 9

[0143] 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 having positive optical power, wherein the object side of the first lens is convex; 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 convex. 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 concave and the image-side surface of the sixth lens is concave. The second lens barrel contains a second lens group, the second lens group having positive optical power, and the second lens group includes: A seventh lens with positive optical power, wherein the object-side surface of the seventh lens is concave and the image-side surface of the seventh lens is convex; 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 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 concave and the image-side surface of the twelfth lens is convex; A fourth spacer element is provided on the image-side surface of the fourth lens; wherein the second lens barrel is movable along the optical axis to achieve zoom; and satisfies: 3.15 < L1 / L2 < 3.65; 4.15<CP4 / (D4s-d4s)<8.45; Wherein, L1 is the maximum thickness of the first lens barrel along the optical axis, L2 is the maximum thickness of the second lens barrel along the optical axis, CP4 is the maximum thickness of the fourth spacer element along the optical axis, D4s is the outer diameter of the side surface of the fourth spacer element, and d4s is the inner diameter of the side surface of the fourth spacer element.

2. 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; the extended lens assembly satisfies: 5.75≤FG1 / CP1≤7.

10. Wherein, FG1 is the combined focal length of the first lens group, and CP1 is the maximum thickness of the first spacer element along the optical axis.

3. 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: -3.70 < F23 / d3s < -3.

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

4. The extended lens assembly according to claim 1, characterized in that, A seventh spacer element is provided on the image-side surface of the seventh lens, and the extended lens assembly satisfies: 1.65 < d7s / CT7 < 2.

55. Wherein, d7s is the inner diameter of the object side of the seventh spacer element, and CT7 is the center thickness of the seventh lens.

5. The extended lens assembly according to claim 1, characterized in that, A tenth spacer element is provided on the image-side surface of the tenth lens, and the extended lens assembly satisfies: 1.55 < LG² / d¹⁰s < 2.

05. Wherein, LG2 is the axial distance from the object side of the seventh lens to the image side of the twelfth lens, and d10s is the inner diameter of the object side of the tenth spacer element.

6. 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: 7.40≤d0bs / CT1≤8.

18. Wherein, d0bs is the inner diameter of the object side of the lens barrel auxiliary element, and CT1 is the center thickness of the first lens.

7. 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: 2.20 < (D3s - d3s) / (D3m - d3m) < 3.

85. Wherein, D3s is the outer diameter of the object side of the third spacer element, d3s is the inner diameter of the object side of the third spacer element, D3m is the outer diameter of the image side of the third spacer element, and d3m is the inner diameter of the image side of the third spacer element.

8. 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; the extended lens assembly satisfies: 1.10 < (d8s + d8m) / F789 < 1.

70. Wherein, d8s is the inner diameter of the object side of the eighth spacer element, d8m is the inner diameter of the image side of the eighth spacer element, and F789 is the combined focal length of the seventh lens, the eighth lens, and the ninth lens.

9. 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: 9.55 < (R6 + R7) / CP3 < 13.

00. Wherein, R6 is the radius of curvature of the image side of the third lens, R7 is the radius of curvature of the object side of the fourth lens, and CP3 is the maximum thickness of the third spacer element along the optical axis.

10. The extended lens assembly according to claim 1, characterized in that, A twelfth spacer element is provided on the image-side surface of the twelfth lens, and the extended lens assembly satisfies: 8.80 < d12m / ΔT < 11.

00. Wherein, d12m is the inner diameter of the image side of the twelfth spacer element, 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.

11. 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: 26.98≤F1234 / CP0b≤31.

17. Wherein, F1234 is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, and CP0b is the maximum thickness of the lens barrel auxiliary element along the optical axis.

12. The extended lens assembly according to claim 1, characterized in that, A twelfth spacer element is provided on the image-side surface of the twelfth lens, and the extended lens assembly satisfies: 4.50 < D12m / CT12 < 5.

65. Wherein, D12m is the outer diameter of the image side of the twelfth spacer element, and CT12 is the center thickness of the twelfth lens.

13. 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: 2.40≤CT2 / (D1m-d1m)≤5.

80. Wherein, CT2 is the center thickness of the second lens, D1m is the outer diameter of the image side of the first spacer element, and d1m is the inner diameter of the image side of the first spacer element.

14. The extended lens assembly according to claim 1, characterized in that, A tenth spacer element is provided on the image-side surface of the tenth lens, and the extended lens assembly satisfies: 0.85 < f11 / d10m < 1.

30. Wherein, f11 is the effective focal length of the eleventh lens, and d10m is the inner diameter of the image-side surface of the tenth 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. A twelfth spacer element is provided on the image-side surface of the twelfth lens, and the extended lens assembly satisfies: 6.70 < FG2 / CP12 < 13.

70. Wherein, FG2 is the combined focal length of the second lens group, and CP12 is the maximum thickness of the twelfth spacer element along the optical axis.

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