Optical system

Abstract

The utility model discloses an optical system, the optical system comprises a lens group and a spacing element group, and the lens group sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image side along an optical axis; the spacing element group comprises a first spacing element and a second spacing element, the first spacing element is arranged on the image side of the first lens and at least partially contacts with the image side surface of the first lens, and the second spacing element is arranged on the image side of the second lens and at least partially contacts with the image side surface of the second lens; the optical system satisfies the following conditions: 3.6 < CT1 / (T12 + CP1) < 4.5 and 3.12 < EP12 / T23 < 4.45. Wherein CT1 is the center thickness of the first lens on the optical axis, T12 is the air interval between the first lens and the second lens on the optical axis, CP1 is the maximum thickness of the first interval element in the optical axis direction, EP12 is the distance from the image side face of the first interval element to the object side face of the second interval element in the optical axis direction, and T3 is the maximum thickness of the first interval element in the optical axis direction. And T23 is an air interval between the second lens and the third lens on the optical axis.

Description

Technical Field

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

[0002] Currently, small-head lenses are widely used in fields such as ranging and tracking. These lenses have relatively few elements, a small lens diameter, and the inner diameter of the spacer elements they use must also be small, severely limiting design freedom. Designing a lens that achieves minimal distortion and field curvature while maintaining a small head and compact size has become a hot topic in the lens design field. In the design process, the spacing between the lenses must be compressed to control the lens size, often leading to assembly stability issues, which in turn affects imaging stability. Utility Model Content

[0003] In a first aspect, the present application provides an optical system comprising: a lens barrel, and a lens group and a spacer group disposed within the lens barrel, wherein the lens group comprises, in order from the object side to the image side along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The spacer group comprises a first spacer element and a second spacer element, wherein the first spacer element is disposed on the image side of the first lens and is in at least partial contact with the image-side surface of the first lens, and the second spacer element is disposed on the image side of the second lens and is in at least partial contact with the image-side surface of the second lens. The number of lenses having optical power in the optical system is six, and the optical system satisfies the following conditions: 3.6<CT1 / (T12+CP1)<4.5 and 3.12<EP12 / T23<4.45; wherein CT1 is the center thickness of the first lens on the optical axis, T12 is the air gap between the first lens and the second lens on the optical axis, CP1 is the maximum thickness of the first spacer element along the optical axis, EP12 is the distance from the image side surface of the first spacer element to the object side surface of the second spacer element along the optical axis, and T23 is the air gap between the second lens and the third lens on the optical axis.

[0004] In one embodiment, the spacer element group includes: a third spacer element and a fourth spacer element, wherein the third spacer element is placed on the image side of the third lens and is in at least partial contact with the image side surface of the third lens, and the fourth spacer element is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; the optical system satisfies: 28.2<f4 / EP34<36.95, wherein f4 is the effective focal length of the fourth lens, and EP34 is the distance from the image side surface of the third spacer element to the object side surface of the fourth spacer element along the optical axis.

[0005] In one embodiment, the spacer element group further includes: a fourth spacer element disposed on the image side of the fourth lens and at least partially in contact with the image side surface of the fourth lens; the optical system satisfies: -2.1<R7 / d4s<-1.3, wherein R7 is the curvature radius of the object side surface of the fourth lens, and d4s is the inner diameter of the object side surface of the fourth spacer element.

[0006] In one embodiment, the spacer element group includes: a fourth spacer element and a fifth spacer element, wherein the fourth spacer element is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens, and the fifth spacer element is placed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; the optical system satisfies: -4.5<f5 / (EP45+CT5)<-2.2, wherein f5 is the effective focal length of the fifth lens, EP45 is the distance from the image side surface of the fourth spacer element to the object side surface of the fifth spacer element along the optical axis, and CT5 is the center thickness of the fifth lens on the optical axis.

[0007] In one embodiment, the spacer element group further includes: a fourth spacer element disposed on the image side of the fourth lens and at least partially in contact with the image side surface of the fourth lens; the optical system satisfies: -2.8<d4m / R9≤-1.8, wherein d4m is the inner diameter of the image side surface of the fourth spacer element, and R9 is the curvature radius of the object side surface of the fifth lens.

[0008] In one embodiment, the spacer element group further includes: a third spacer element disposed on the image side of the third lens and at least partially in contact with the image side surface of the third lens; the optical system satisfies: 6.32<f3 / (EP23+T34)<8.68, wherein f3 is the effective focal length of the third lens, EP23 is the distance from the image side surface of the second spacer element to the object side surface of the third spacer element along the optical axis, and T34 is the air gap between the third lens and the fourth lens on the optical axis.

[0009] In one embodiment, the optical system satisfies: 1.62<D0m / R12<4.55, wherein D0m is the outer diameter of the image-side end surface of the lens barrel, and R12 is the curvature radius of the image-side surface of the sixth lens.

[0010] In one embodiment, the optical system satisfies: 4.95<f1 / EP01<7.05, wherein f1 is the effective focal length of the first lens, and EP01 is the distance from the object side end surface of the lens barrel to the object side surface of the first spacer element along the optical axis.

[0011] In one embodiment, the optical system satisfies: 1.6<(d1s+d1m) / R1<2.15, where d1s is the inner diameter of the object side surface of the first spacer element, d1m is the inner diameter of the image side surface of the first spacer element, and R1 is the curvature radius of the object side surface of the first lens.

[0012] In one embodiment, the optical system satisfies: 1.0<D1s / R2<1.45, wherein D1s is the outer diameter of the object-side surface of the first spacer element, and R2 is the curvature radius of the image-side surface of the first lens.

[0013] In one embodiment, the optical system satisfies: 1.0≤(R3×D1m) / (R4×D2s)<1.45, wherein R3 is the curvature radius of the object side surface of the second lens, R4 is the curvature radius of the image side surface of the second lens, D1m is the outer diameter of the image side surface of the first spacer element, and D2s is the outer diameter of the object side surface of the second spacer element.

[0014] In one embodiment, the optical system satisfies: 2.05<R5 / d2m<3.1, wherein R5 is the curvature radius of the object-side surface of the third lens, and d2m is the inner diameter of the image-side surface of the second spacer element.

[0015] In one embodiment, the spacer element group further includes: a third spacer element disposed on the image side of the third lens and at least partially in contact with the image side surface of the third lens; the optical system satisfies: -30.4<R6 / d3s<-7.5, wherein R6 is the radius of curvature of the image side surface of the third lens, and d3s is the inner diameter of the object side surface of the third spacer element.

[0016] In one embodiment, the optical system satisfies: -31.05<f2 / (CP1+EP12+CP2)<-22.65, where f2 is the effective focal length of the second lens, CP1 is the maximum thickness of the first spacer element along the optical axis, CP2 is the maximum thickness of the second spacer element along the optical axis, and EP12 is the distance from the image side surface of the first spacer element to the object side surface of the second spacer element along the optical axis.

[0017] In one embodiment, the spacer element group further includes: a fifth spacer element disposed on the image side of the fifth lens and at least partially in contact with the image side surface of the fifth lens; the optical system satisfies: -1.0<(R10 / D5s) / (R11 / D5m)<-0.52, wherein R10 is the curvature radius of the image side surface of the fifth lens, R11 is the curvature radius of the object side surface of the sixth lens, D5s is the outer diameter of the object side surface of the fifth spacer element, and D5m is the outer diameter of the image side surface of the fifth spacer element.

[0018] In one embodiment, the optical system satisfies: 0.75 mm < d1s < 1.05 mm and 0.9 mm < d2s < 1.1 mm, wherein d1s is the inner diameter of the object-side surface of the first spacer element, and d2s is the inner diameter of the object-side surface of the second spacer element.

[0019] In one embodiment, the object-side surface of the first lens is convex, and the image-side surface is concave; the object-side surface of the second lens is convex, and the image-side surface is concave; the object-side surface of the third lens is convex, and the image-side surface is convex; the object-side surface of the fourth lens is concave, and the image-side surface is convex; the object-side surface of the fifth lens is concave, and the image-side surface is convex; the object-side surface of the sixth lens is convex, and the image-side surface is concave.

[0020] According to a second aspect of the present application, an optical system is provided, comprising: a lens barrel, and a lens group and a spacer element group disposed in the lens barrel, wherein the lens group comprises, in order from the object side to the image side along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The spacer element group comprises: a first spacer element and a second spacer element, wherein the first spacer element is disposed on the image side of the first lens and is in at least partial contact with the image side surface of the first lens, and the second spacer element is disposed on the image side of the second lens and is in at least partial contact with the image side surface of the second lens. The optical system satisfies 1.0≤(R3×D1m) / (R4×D2s)<1.45, wherein R3 is the radius of curvature of the object side surface of the second lens, R4 is the radius of curvature of the image side surface of the second lens, D1m is the outer diameter of the image side surface of the first spacer element, and D2s is the outer diameter of the object side surface of the second spacer element.

[0021] In a third aspect, the present application provides an optical system comprising: a lens barrel, and a lens group and a spacer element group disposed within the lens barrel, wherein the lens group comprises, in order from the object side to the image side along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The spacer element group comprises: a first spacer element and a second spacer element, wherein the first spacer element is disposed on the image side of the first lens and is in at least partial contact with the image side surface of the first lens, and the second spacer element is disposed on the image side of the second lens and is in at least partial contact with the image side surface of the second lens. The optical system satisfies -31.05<f2 / (CP1+EP12+CP2)<-22.65, wherein f2 is the effective focal length of the second lens, CP1 is the maximum thickness of the first spacer element along the optical axis, CP2 is the maximum thickness of the second spacer element along the optical axis, and EP12 is the distance from the image side surface of the first spacer element to the object side surface of the second spacer element along the optical axis.

[0022] The present application provides a six-element optical system that satisfies 3.6<CT1 / (T12+CP1)<4.5 and 3.12<EP12 / T23<4.45, and can effectively limit the position of the first lens to the third lens, so that the force deformation thereof is small, and the deformation has a weak effect on the MTF, and the overall sensitivity is minimized, thereby ensuring assembly stability, which is conducive to achieving the characteristics of a compact lens structure and a small head, and is also conducive to correcting off-axis aberrations and improving the overall image quality of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0024] Figure 1 A schematic diagram showing the structural arrangement of an optical system and some parameters according to the present application is shown;

[0025] Figure 2A 1 shows a schematic structural diagram of an optical system according to Example 1 of the present application;

[0026] Figure 2B 1 shows a schematic structural diagram of an optical system according to Example 2 of the present application;

[0027] Figures 3A to 3D The axial chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical systems according to Example 1 and Example 2 of the present application are respectively shown;

[0028] Figure 4A 1 shows a schematic structural diagram of an optical system according to Example 3 of the present application;

[0029] Figure 4B 1 shows a schematic structural diagram of an optical system according to Example 4 of the present application;

[0030] 5A to 5D The axial chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical systems according to Example 3 and Example 4 of the present application are respectively shown;

[0031] Figure 6A 1 shows a schematic structural diagram of an optical system according to Example 5 of the present application;

[0032] Figure 6B 1 shows a schematic structural diagram of an optical system according to Example 6 of the present application;

[0033] 7A to 7D The axial chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical systems according to Example 5 and Example 6 of the present application are respectively shown;

[0034] Figure 8A 1 shows a schematic structural diagram of an optical system according to Example 7 of the present application;

[0035] Figure 8B 1 shows a schematic structural diagram of an optical system according to Example 8 of the present application;

[0036] 9A to 9DThe axial chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical systems according to Example 7 and Example 8 of the present application are respectively shown;

[0037] Figure 10 This is a schematic diagram of the center point and edge points of the lens. DETAILED DESCRIPTION

[0038] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of exemplary embodiments of the present application and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0039] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of this application.

[0040] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0041] Those skilled in the art will understand that a lens is an optical component formed by two refractive surfaces surrounding a transparent medium. The refractive surface can be a spherical surface (including a plane, i.e. a spherical surface with an infinite radius of curvature) or an aspherical surface. The line connecting the centers of curvature of the two refractive surfaces is the optical axis of the lens. In this article, the surface of the two refractive surfaces closer to the object is called the object side of the lens, and the surface closer to the imaging surface is called the image side of the lens. Each side has a center point and an edge point. For example, Figure 10 The center point A and edge point B of the image-side surface of the first lens E1 are shown. The center point is a special point in the middle of the lens where light does not change its propagation direction. The edge point is the point of the lens with the maximum effective aperture away from the optical axis.

[0042] In this article, the paraxial area refers to the area near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial area; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial area. The judgment of the surface shape in the paraxial area can be judged according to the common methods in this field, for example, the positive and negative R value (R refers to the curvature radius of the paraxial area) is used to judge the convexity. For the object side, when the R value is positive, it is judged to be convex, and when the R value is negative, it is judged to be concave; for the image side, when the R value is positive, it is judged to be concave, and when the R value is negative, it is judged to be convex.

[0043] The solutions described in the embodiments of the present application can be simulated by software / tools such as ZEMAX and CODE V. For example, the solutions described in some embodiments can be simulated preferably by CODE V. In the process of simulation using software / tools such as the above, the surface shape of the lens can be appropriately adjusted according to the surface shape model of the software / tool used. It should also be understood that the terms "include", "including", "having", "containing" and / or "containing", 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. In addition, when a statement such as "at least one of..." appears after a list of listed features, it modifies the entire listed features rather than modifying individual elements in the list. In addition, when describing the embodiments of the present application, "may" is used to indicate "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0044] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0045] It should be noted that, in the absence of any conflict, the embodiments and features of the embodiments in this application can be combined with each other. The following embodiments only express several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they should not be understood as limiting the scope of the patent of this application. It should be pointed out that for those skilled in the art, several variations and improvements can be made without departing from the concept of the present application, and these all fall within the scope of protection of this application. For example, the lens groups, lens barrels, and spacer elements in the various embodiments of the present application can be combined arbitrarily, and are not limited to the lens group in one embodiment being combined only with the lens barrel, spacer element, etc. of that embodiment.

[0046] The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0047] An optical system according to an exemplary embodiment of the present application includes a lens barrel, a lens assembly disposed within the lens barrel, and a spacer assembly. The lens assembly may include six lenses having optical power, namely, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The six lenses are arranged in sequence along the optical axis from the object side to the image side. Any two adjacent lenses among the first to sixth lenses may be spaced apart by a distance.

[0048] In example embodiments, the first lens may have positive power, the second lens may have negative power, the third lens may have positive power, the fourth lens may have positive power, the fifth lens may have negative power, and the sixth lens may have positive or negative power.

[0049] In an exemplary embodiment, the object-side surfaces of the first lens, the second lens, and the sixth lens are convex, and the image-side surfaces are concave.

[0050] In an exemplary embodiment, the object-side surface of the third lens is convex, and the image-side surface is convex.

[0051] In an exemplary embodiment, the object-side surfaces of the fourth lens and the fifth lens are concave, and the image-side surfaces are convex.

[0052] In an exemplary embodiment, the spacer element group of the optical system may include a first spacer element and a second spacer element, wherein the first spacer element is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens, and the second spacer element is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens.

[0053] In an exemplary embodiment, the spacer element group of the optical system may include at least one of a first spacer element, a second spacer element, a third spacer element, a fourth spacer element, a fifth spacer element, and a sixth spacer element. The first spacer element is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens. The second spacer element is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens. The third spacer element is positioned on the image side of the third lens and is in at least partial contact with the image side surface of the third lens. The fourth spacer element is positioned on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens. The fifth spacer element is positioned on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens. The sixth spacer element is positioned on the image side of the sixth lens and is in at least partial contact with the image side surface of the sixth lens.

[0054] In an exemplary embodiment, the spacer element group of the optical system may include a fifth spacer element, a fifth auxiliary spacer element, and a fifth-sub-auxiliary spacer element. The fifth spacer element is positioned on the image side of the fifth lens element and is in at least partial contact with the image-side surface of the fifth lens element. The fifth auxiliary spacer element is positioned on the image side of the fifth spacer element and is in at least partial contact with the image-side surface of the fifth spacer element. The fifth-sub-auxiliary spacer element is positioned on the image side of the fifth auxiliary spacer element and is in at least partial contact with the image-side surface of the fifth auxiliary spacer element.

[0055] It should be understood that this application does not specifically limit the number of spacer elements; any number of spacer elements may be included between any two lenses, and the entire optical system may also include any number of spacer elements. Spacer elements help the optical system intercept excess refractive and reflective light paths, reducing stray light and ghosting. Spacer elements also help provide additional support between the lenses and the lens barrel, helping to alleviate issues such as poor assembly stability and low performance yield caused by large step differences between lenses.

[0056] Figure 1 The following is a schematic diagram of the structure of an optical system and a schematic diagram of some parameters according to the present application. Figure 1As shown, CP1 is the maximum thickness of the first spacer element along the optical axis, CP2 is the maximum thickness of the second spacer element along the optical axis, EP01 is the distance from the object side end face of the lens barrel to the object side face of the first spacer element along the optical axis, EP12 is the distance from the image side face of the first spacer element to the object side face of the second spacer element along the optical axis, EP23 is the distance from the image side face of the second spacer element to the object side face of the third spacer element along the optical axis, EP34 is the distance from the image side face of the third spacer element to the object side face of the fourth spacer element along the optical axis, and EP45 is the distance from the image side face of the fourth spacer element to the object side face of the fifth spacer element along the optical axis. d1s is the inner diameter of the object side surface of the first spacer element, d1m is the inner diameter of the image side surface of the first spacer element, d2m is the inner diameter of the image side surface of the second spacer element, d3s is the inner diameter of the object side surface of the third spacer element, d4s is the inner diameter of the object side surface of the fourth spacer element, d4m is the inner diameter of the image side surface of the fourth spacer element, D1s is the outer diameter of the object side surface of the first spacer element, D1m is the outer diameter of the image side surface of the first spacer element, D2s is the outer diameter of the object side surface of the second spacer element, D5s is the outer diameter of the object side surface of the fifth spacer element, D5m is the outer diameter of the image side surface of the fifth spacer element, and D0m is the outer diameter of the image side end surface of the lens barrel.

[0057] It should be understood by those skilled in the art that some parameters of lenses commonly used in the art (such as the center thickness CT1 of the first lens on the optical axis) are not specified in the present invention. Figure 1 As shown in Figure 1 Only partial parameters of the lens barrel and the spacer element of an optical system of the present application are exemplified to facilitate a better understanding of the present invention.

[0058] In an exemplary embodiment, a lens assembly may include at least one trimmed lens. The outer periphery of the trimmed lens may have a trimmed portion and an untrimmed portion, with the outer diameter of the trimmed portion being smaller than the outer diameter of the untrimmed portion. When the outer periphery of a lens has a trimmed portion, the outer diameter of the lens generally refers to the outer diameter of the untrimmed portion of the lens.

[0059] In an exemplary embodiment, the spacer element set may include at least one trimmed spacer element. The outer circumference of the trimmed spacer element may have a trimmed portion and a non-trimmed portion, and the outer diameter of the trimmed portion of the spacer element is smaller than the outer diameter of the non-trimmed portion of the spacer element. The outer diameter of the spacer element generally refers to the maximum outer diameter of the non-trimmed portion.

[0060] In an exemplary embodiment, the optical system according to the present application can satisfy the following condition: 3.6 < CT1 / (T12 + CP1) < 4.5, where CT1 is the center thickness of the first lens on the optical axis, T12 is the air gap between the first and second lenses on the optical axis, and CP1 is the maximum thickness of the first spacer along the optical axis. By controlling the center thickness of the first lens on the optical axis, the air gap between the first and second lenses on the optical axis, and the maximum thickness of the first spacer along the optical axis, the supporting relationship between the first lens, the first spacer, and the second lens can be optimally coordinated, achieving a compact lens structure and improving the stability of the optical system assembly.

[0061] In an exemplary embodiment, the optical system according to the present application can satisfy the following condition: 3.12 < EP12 / T23 < 4.45, where EP12 is the distance along the optical axis from the image side surface of the first spacer element to the object side surface of the second spacer element, and T23 is the air spacing between the second and third lenses on the optical axis. Controlling the distance along the optical axis from the image side surface of the first spacer element to the object side surface of the second spacer element effectively controls the edge thickness of the second lens; controlling the air spacing between the second and third lenses on the optical axis constrains the center thickness of the second lens. Therefore, satisfying 3.12 < EP12 / T23 < 4.45 facilitates controlling the thickness ratio of the second lens and ensures its manufacturability.

[0062] An optical system according to an exemplary embodiment of the present application includes: a lens barrel, and a lens group and a spacer group disposed within the lens barrel. The lens group includes, in order from the object side to the image side along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The spacer group includes a first spacer and a second spacer. The first spacer is disposed on the image side of the first lens and is in at least partial contact with the image-side surface of the first lens, and the second spacer is disposed on the image side of the second lens and is in at least partial contact with the image-side surface of the second lens. The optical system satisfies the conditions 3.6 < CT1 / (T12 + CP1) < 4.5 and 3.12 < EP12 / T23 < 4.45, where CT1 is the center thickness of the first lens on the optical axis, T12 is the air spacing between the first and second lenses on the optical axis, CP1 is the maximum thickness of the first spacer along the optical axis, EP12 is the distance along the optical axis from the image-side surface of the first spacer to the object-side surface of the second spacer, and T23 is the air spacing between the second and third lenses on the optical axis. Meeting the requirements of 3.6<CT1 / (T12+CP1)<4.5 and 3.12<EP12 / T23<4.45 can effectively limit the positions of the first to third lenses, causing them to undergo less force deformation, with the deformation having a weak effect on MTF, minimizing the overall sensitivity, and thus ensuring assembly stability. This is conducive to achieving a compact lens structure, correcting off-axis aberrations, and improving the overall image quality of the system.

[0063] The following, combined with Tables 1-1 to 1-4, further illustrates that the optical system of the present application exhibits excellent assembly stability and guaranteed MTF peak stability when meeting the conditions 3.6 < CT1 / (T12+CP1) < 4.5 and 3.12 < EP12 / T23 < 4.45. For example, the second lenses of Optical System 1, Optical System 2, and Optical System 3 in Tables 1-1 to 1-4 all have relatively large and sensitive refractive indices. Tables 1-1 to 1-4 show the differences in structural stability and MTF peak stability for these three optical systems when meeting different values of CT1 / (T12+CP1) and EP12 / T23.

[0064] Table 1-1 shows the changes in the center and edge of the first and second lenses relative to their design values (i.e., center point displacement and edge point displacement), as well as the structural sensitivity of the air gap between the first and second lenses on the optical axis when the same load is applied to the three optical systems. More specifically, ΔSp1 represents the structural sensitivity of the air gap between the first and second lenses on the optical axis when a certain load is applied to the optical system (i.e., the change in the gap between the center area of the first and second lenses). When the same load is applied to the structural area (i.e., the non-effective diameter portion) of optical system 1, optical system 2, and optical system 3, a deformation is generated when the force is transferred from the edge position to the center position of the structural area. For example, when the structural area of the image side surface of the second lens of optical system 1, optical system 2, and optical system 3 is subjected to the same external force, the edge position and center position of the first and second lenses are deformed under the influence of stress, which in turn causes the air gap between the first and second lenses to change. For example, referring to Table 1-1, through simulation, the structural sensitivity ΔSp1 of optical system 1, optical system 2 and optical system 3 are -0.3665μm, -4.554μm and -2.938μm respectively. It can be seen that the structural sensitivity ΔSp1 of optical system 1 is smaller, that is, the displacement is smaller, and the structural sensitivity of optical system 1 is better.

[0065] The units of center point displacement, edge point displacement and ΔSp1 in Table 1-1 are all micrometers (μm).

[0066] ΔSp1=(the air gap between the first lens and the second lens on the optical axis−the center thickness of the second lens on the optical axis)×1000.

[0067] ΔSp1 of the optical system 1 = (4.25E-05 - 4.09E-04) × 1000 = -0.3665 μm.

[0068] ΔSp1 of the optical system 2 = (4.96E-04 - 5.05E-03) × 1000 = -4.554 μm.

[0069] ΔSp1 of the optical system 3 = (5.72E-04 - 3.51E-03) × 1000 = -2.938 μm.

[0070]

[0071] Table 1-1

[0072] In Table 1-1, optical system 1 meets the ranges of 3.6 < CT1 / (T12+CP1) < 4.5 and 3.12 < EP12 / T23 < 4.45 specified in this application, while optical systems 2 and 3 do not meet the ranges of 3.6 < CT1 / (T12+CP1) < 4.5 and 3.12 < EP12 / T23 < 4.45 specified in this application. The center point displacement, edge point displacement, and ΔSp1 of optical system 1 are significantly smaller than those of optical systems 2 and 3, respectively, indicating that optical system 1 has superior stability. In other words, when the values of CT1 / (T12+CP1) and EP12 / T23 are both within the ranges specified in this application, the change in the air gap between the first and second lens elements after lens assembly is minimal. However, when the values of CT1 / (T12+CP1) and EP12 / T23 are outside the ranges specified in this application, the change in the air gap between the first and second lens elements after lens assembly is significant.

[0073] Table 1-2 shows the changes in the center and edge of the second and third lenses relative to their design values (i.e., center point displacement and edge point displacement), respectively, and the structural sensitivity of the air gap between the second and third lenses on the optical axis when the same load is applied to the three optical systems. More specifically, ΔSp2 represents the structural sensitivity of the air gap between the second and third lenses on the optical axis (i.e., the change in the gap between the center regions of the second and third lenses) when a certain load is applied to the optical system. Applying the same load to the structural region (i.e., the non-effective diameter portion) of Optical System 1, Optical System 2, and Optical System 3 results in a deformation caused by the force being transferred from the edge to the center of the structural region. For example, when the structural region of the image side surface of the third lens of Optical System 1, Optical System 2, and Optical System 3 is subjected to the same external force, the stress causes deformation at both the edge and center of the second and third lenses, resulting in a change in the air gap between the second and third lenses. For example, referring to Table 1-2, through simulation, the structural sensitivity ΔSp2 of optical system 1, optical system 2 and optical system 3 are 0.3358μm, 2.322μm and 3.298μm respectively. It can be seen that the structural sensitivity ΔSp2 of optical system 1 is smaller, that is, the displacement is smaller, and the structural sensitivity of optical system 1 is better.

[0074] The units of center point displacement, edge point displacement and ΔSp2 in Table 1-2 are all micrometers (μm).

[0075] ΔSp2=(the air gap between the second lens and the third lens on the optical axis−the center thickness of the third lens on the optical axis)×1000.

[0076] ΔSp2 of the optical system 1 = (4.32E-04 - 9.62E-05) × 1000 = 0.3358 μm.

[0077] ΔSp2 of the optical system 2 = (2.85E-03 - 5.28E-04) × 1000 = 2.322 μm.

[0078] ΔSp2 of the optical system 3 = (4.05E-03 - 7.52E-04) × 1000 = 3.298 μm.

[0079]

[0080]

[0081] Table 1-2

[0082] In Table 1-2, Optical System 1 meets the ranges of 3.6 < CT1 / (T12+CP1) < 4.5 and 3.12 < EP12 / T23 < 4.45 specified in this application. Optical Systems 2 and 3 do not meet the ranges of 3.6 < CT1 / (T12+CP1) < 4.5 and 3.12 < EP12 / T23 < 4.45 specified in this application. The center point displacement, edge point displacement, and ΔSp2 of Optical System 1 are significantly smaller than those of Optical Systems 2 and 3, respectively, indicating that Optical System 1 has superior stability. In other words, when the values of CT1 / (T12+CP1) and EP12 / T23 are both within the ranges specified in this application, the change in the air gap between the second and third lenses after lens assembly is minimal. However, when the values of CT1 / (T12+CP1) and EP12 / T23 are outside the ranges specified in this application, the change in the air gap between the second and third lenses after lens assembly is significant.

[0083] Table 1-3 shows the change in the MTF peak value of the edge field of view (1.0F) when the spatial spacing between the first lens and the second lens on the optical axis changes by +3μm and -3μm, that is, Table 1-3 is an analysis table of the optical sensitivity of the edge field of view of the air spacing between the first lens and the second lens on the optical axis of the three optical systems. In other words, the optical sensitivity indicates the change in the MTF peak value of the edge field of view of the lens when the displacement of the lens is constant. In Table 1-3, the symbols "+" and "-" in +3μm and -3μm indicate the direction of fluctuation of the spatial spacing between the two adjacent lenses compared to the design value. The MTF peak value is in percentage (%) and has no unit. More specifically, the change in the MTF peak value is the change in the MTF peak value at a spatial frequency of 87p / mm.

[0084] Referring to Tables 1-3, through simulation, when the spatial interval between the first lens and the second lens on the optical axis changes by +3μm, the changes in the MTF peak values of the edge field of view of optical systems 1, 2, and 3 are -0.6%, -1.2%, and -1.0%, respectively; when the spatial interval between the first lens and the second lens on the optical axis changes by -3μm, the changes in the MTF peak values of the edge field of view of optical systems 1, 2, and 3 are 0.1%, 0.4%, and -0.3%, respectively. It can be seen that the MTF peak value of optical system 1 is less affected by deformation, and optical system 1 has better optical sensitivity.

[0085]

[0086] Table 1-3

[0087] Table 1-4 shows the change in the MTF peak value of the edge field of view (1.0F) when the spatial spacing between the second lens and the third lens of the three optical systems on the optical axis changes by +3μm and -3μm, that is, Table 1-4 is an analysis table of the optical sensitivity of the edge field of view of the air spacing between the second lens and the third lens of the three optical systems on the optical axis. In other words, the optical sensitivity indicates the change in the MTF peak value of the edge field of view of the lens when the displacement of the lens is constant. In Table 1-4, the symbols "+" and "-" in +3μm and -3μm indicate the direction of fluctuation of the spatial spacing between the two adjacent lenses compared to the design value. The MTF peak value is in percentage (%) and has no unit. More specifically, the change in the MTF peak value is the change in the MTF peak value at the spatial frequency of 87p / mm.

[0088] Referring to Tables 1-4, through simulation, when the spatial interval between the second lens and the third lens on the optical axis changes by +3μm, the changes in the MTF peak values of the edge field of view of optical systems 1, 2, and 3 are -0.3%, -0.8%, and -0.6%, respectively; when the spatial interval between the second lens and the third lens on the optical axis changes by -3μm, the changes in the MTF peak values of the edge field of view of optical systems 1, 2, and 3 are 0%, -0.2%, and -0.2%, respectively. It can be seen that the MTF peak value of optical system 1 is less affected by deformation, and optical system 1 has better optical sensitivity.

[0089]

[0090]

[0091] Table 1-4

[0092] In summary, based on the analysis of Tables 1-1 to 1-4 above, it can be seen that optical system 1 meets the requirements of 3.6 < CT1 / (T12 + CP1) < 4.5 and 3.12 < EP12 / T23 < 4.45 specified in this application. The force deformation of the first through third lenses is small, and the deformation has a weak effect on MTF. The overall sensitivity is minimized, and the assembly stability is good.

[0093] In an exemplary embodiment, the optical system according to the present application can satisfy the following: 28.2 < f4 / EP34 < 36.95, where f4 is the effective focal length of the fourth lens element, and EP34 is the distance along the optical axis from the image side surface of the third spacer element to the object side surface of the fourth spacer element. By controlling the effective focal length of the fourth lens element and the distance along the optical axis from the image side surface of the third spacer element to the object side surface of the fourth spacer element, the edge thickness of the fourth lens can be controlled while balancing system spherical aberration, reducing the difficulty of molding the fourth lens and improving assembly stability.

[0094] In an exemplary embodiment, the optical system according to the present application can satisfy the following relationship: -2.1 < R7 / d4s < -1.3, where R7 is the radius of curvature of the object-side surface of the fourth lens element, and d4s is the inner diameter of the object-side surface of the fourth spacer element. By controlling the radius of curvature of the object-side surface of the fourth lens element and the inner diameter of the object-side surface of the fourth spacer element, the height of the lens barrel can be effectively controlled, achieving an ultra-thin lens and reducing its size. This also helps enhance the stray light mitigation effect of the fourth spacer element, thereby improving the imaging quality of the lens.

[0095] In an exemplary embodiment, the optical system according to the present application can satisfy the following relationship: -4.5 < f5 / (EP45 + CT5) < -2.2, where f5 is the effective focal length of the fifth lens element, EP45 is the distance along the optical axis from the image side surface of the fourth spacer element to the object side surface of the fifth spacer element, and CT5 is the center thickness of the fifth lens on the optical axis. Properly controlling the relationship between the effective focal length of the fifth lens, the center thickness of the fifth lens on the optical axis, and the distance along the optical axis from the image side surface of the fourth spacer element to the object side surface of the fifth spacer element can cause incident light to converge from the fourth lens to the fifth lens, thereby ensuring a larger margin of air space between the fourth and fifth lenses on the optical axis. Furthermore, the thickness ratio of the fifth lens can be controlled, ensuring the machinability of the fifth lens and improving assembly stability.

[0096] In an exemplary embodiment, the optical system according to the present application can satisfy the following condition: -2.8 < d4m / R9 ≤ -1.8, where d4m is the inner diameter of the image-side surface of the fourth spacer element, and R9 is the radius of curvature of the object-side surface of the fifth lens. Properly controlling the relationship between the inner diameter of the image-side surface of the fourth spacer element and the radius of curvature of the object-side surface of the fifth lens helps ensure lens performance and imaging quality, controls the state of light emitted from the fourth and fifth lenses, and thereby influences the imaging effect of the lens. Controlling the inner diameter of the image-side surface of the fourth spacer element also helps prevent internal reflected stray light from entering the optical system, which can affect the imaging quality of the lens.

[0097] In an exemplary embodiment, the optical system according to the present application can satisfy the following condition: 6.32 < f3 / (EP23 + T34) < 8.68, where f3 is the effective focal length of the third lens, EP23 is the distance along the optical axis from the image side surface of the second spacer element to the object side surface of the third spacer element, and T34 is the air spacing between the third lens and the fourth lens on the optical axis. By controlling the effective focal length of the third lens and the distance along the optical axis from the image side surface of the second spacer element to the object side surface of the third spacer element, the shape of the off-axis region of the third lens can be controlled, enabling the third lens to control the amount of astigmatism of the optical system, improving the imaging quality of the off-axis field of view while maintaining assembly stability and avoiding interference with other elements.

[0098] In an exemplary embodiment, the optical system according to the present application can satisfy the following relationship: 1.62 < D0m / R12 < 4.55, where D0m is the outer diameter of the image-side end surface of the lens barrel, and R12 is the radius of curvature of the image-side surface of the sixth lens. By controlling the relationship between the outer diameter of the image-side end surface of the lens barrel and the radius of curvature of the image-side surface of the sixth lens, stray light generated by the image-side end surface of the lens barrel and stray light generated by reflections between the lens barrel and the chip can be effectively limited.

[0099] In an exemplary embodiment, the optical system according to the present application can satisfy the following relationship: 4.95 < f1 / EP01 < 7.05, where f1 is the effective focal length of the first lens element, and EP01 is the distance along the optical axis from the object-side end face of the lens barrel to the object-side face of the first spacer element. By controlling the distance between the object-side end face of the lens barrel and the object-side face of the first spacer element, the thickness of the object-side end of the lens barrel can be increased, thereby improving assembly stability.

[0100] In an exemplary embodiment, the optical system according to the present application can satisfy the following: 1.6 < (d1s + d1m) / R1 < 2.15, where d1s is the inner diameter of the object-side surface of the first spacer element, d1m is the inner diameter of the image-side surface of the first spacer element, and R1 is the radius of curvature of the object-side surface of the first lens. By controlling the inner diameter of the first spacer element and the radius of curvature of the first lens, it is possible to manage the radial dimensions of the first spacer element, ensuring that ineffective light is blocked between the first and second lenses. A larger blocked area blocks more ineffective light, thus contributing to overall improvement in lens stray light.

[0101] In an exemplary embodiment, the optical system according to the present application can satisfy the following condition: 1.0 < D1s / R2 < 1.45, where D1s is the outer diameter of the object-side surface of the first spacer element, and R2 is the radius of curvature of the image-side surface of the first lens. By controlling the outer diameter of the object-side surface of the first spacer element and the radius of curvature of the image-side surface of the first lens, the angle of light emitted from the first lens can be reduced, thereby reducing reflected stray light from the rear optical system.

[0102] In an exemplary embodiment, the optical system according to the present application may satisfy: 1.0≤(R3×D1m) / (R4×D2s)<1.45, wherein R3 is the curvature radius of the object side surface of the second lens, R4 is the curvature radius of the image side surface of the second lens, D1m is the outer diameter of the image side surface of the first spacer element, and D2s is the outer diameter of the object side surface of the second spacer element. By controlling the curvature radii of the object side and image side surfaces of the second lens, the outer diameter of the image side surface of the first spacer element, and the curvature radius of the image side surface of the second lens, it is beneficial to control the step difference between the second spacer element and the third spacer element within an appropriate range, and it is also beneficial to ensure the stability of the lens assembly. For example, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens determine the overall profile of the second lens to a certain extent. The outer diameter D1m of the object side surface of the first spacer element determines the contact area between the first spacer element and the object side surface of the second lens. The outer diameter D2s of the object side surface of the second spacer element determines the contact area between the second spacer element and the image side surface of the first lens. Therefore, satisfying 1.0≤(R3×D1m) / (R4×D2s)<1.45 is beneficial to ensuring better assembly stability of the second lens, and thus ensuring the stability of the lens assembly.

[0103] In an exemplary embodiment, the optical system according to the present application can satisfy the following relationship: 2.05 < R5 / d2m < 3.1, where R5 is the radius of curvature of the object-side surface of the third lens element, and d2m is the inner diameter of the image-side surface of the second spacer element. Controlling the radius of curvature of the object-side surface of the third lens element helps constrain the thickness of the third spacer element, allowing ample adjustment during assembly to correct for field curvature. Controlling the inner diameter of the image-side surface of the second spacer element also helps block stray light.

[0104] In an exemplary embodiment, the optical system according to the present application can satisfy the following conditions: -30.4 < R6 / d3s < -7.5, where R6 is the radius of curvature of the image-side surface of the third lens element, and d3s is the inner diameter of the object-side surface of the third spacer element. Properly setting the radius of curvature of the image-side surface of the third lens element and the inner diameter of the object-side surface of the third spacer element helps improve the assembly stability of the lenses behind the third lens element (i.e., the fourth through sixth lenses), and also helps limit the amount of assembly deformation of the third lens element and ensure strength.

[0105] In an exemplary embodiment, the optical system according to the present application can satisfy the following condition: -31.05 < f2 / (CP1 + EP12 + CP2) < -22.65, where f2 is the effective focal length of the second lens element, CP1 is the maximum thickness of the first spacer element along the optical axis, CP2 is the maximum thickness of the second spacer element along the optical axis, and EP12 is the distance from the image side surface of the first spacer element to the object side surface of the second spacer element along the optical axis. By controlling the effective focal length of the second lens element, the maximum thickness of the first spacer element along the optical axis, and the maximum thickness of the second spacer element along the optical axis, the edge thickness of the second lens can be effectively controlled, improving the ultimate manufacturing process during lens production and thereby enhancing the stability of lens assembly.

[0106] In an exemplary embodiment, the optical system according to the present application can satisfy the following: -1.0 < (R10 / D5s) / (R11 / D5m) < -0.52, where R10 is the radius of curvature of the image-side surface of the fifth lens element, R11 is the radius of curvature of the object-side surface of the sixth lens element, D5s is the outer diameter of the object-side surface of the fifth spacer element, and D5m is the outer diameter of the image-side surface of the fifth spacer element. Satisfying -1.0 < (R10 / D5s) / (R11 / D5m) < -0.52 is beneficial for ensuring the assembly requirements of the optical system. The radius of curvature R10 of the image-side surface of the fifth lens and the radius of curvature R11 of the object-side surface of the sixth lens affect the surface profiles of the fifth and sixth lenses. Furthermore, the closer the outer diameters of the object-side surface of the fifth spacer element are to the outer diameters of the image-side surface, the more significant the improvement in lens assembly stability, and the better the lens assembly stability.

[0107] In an exemplary embodiment, the optical system according to the present application can meet the following requirements: 0.75mm < d1s < 1.05mm and 0.9mm < d2s < 1.1mm, where d1s is the inner diameter of the object-side surface of the first spacer element, and d2s is the inner diameter of the object-side surface of the second spacer element. For small-head lenses, the lens diameter is small, and the inner diameter of the spacer element used with it should also be small. Properly controlling the inner diameters of the first and second spacer elements within a reasonable range helps intercept non-significant light while ensuring a reasonable amount of light transmission.

[0108] According to an exemplary embodiment of the present application, an optical system includes: a lens barrel and a lens group and a spacer element group disposed in the lens barrel, wherein the lens group includes, in order from the object side to the image side along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The spacer element group includes: a first spacer element and a second spacer element, wherein the first spacer element is disposed on the image side of the first lens and is in at least partial contact with the image side surface of the first lens, and the second spacer element is disposed on the image side of the second lens and is in at least partial contact with the image side surface of the second lens. The optical system satisfies 1.0≤(R3×D1m) / (R4×D2s)<1.45, wherein R3 is the radius of curvature of the object side surface of the second lens, R4 is the radius of curvature of the image side surface of the second lens, D1m is the outer diameter of the image side surface of the first spacer element, and D2s is the outer diameter of the object side surface of the second spacer element. The curvature radius R3 of the object-side surface of the second lens and the curvature radius R4 of the image-side surface of the second lens determine, to a certain extent, the overall profile of the second lens. The outer diameter D1m of the object-side surface of the first spacer element determines the contact area between the first spacer element and the object-side surface of the second lens. The outer diameter D2s of the object-side surface of the second spacer element determines the contact area between the second spacer element and the image-side surface of the first lens. Therefore, satisfying 1.0≤(R3×D1m) / (R4×D2s)<1.45 is beneficial for controlling the step difference between the second spacer element and the third spacer element within an appropriate range, and also helps to ensure better assembly stability of the second lens, thereby ensuring the required lens assembly stability.

[0109] According to an exemplary embodiment of the present application, an optical system includes: a lens barrel and a lens group and a spacer element group disposed in the lens barrel, wherein the lens group includes, in order from the object side to the image side along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The spacer element group includes: a first spacer element and a second spacer element, wherein the first spacer element is disposed on the image side of the first lens and is in at least partial contact with the image side surface of the first lens, and the second spacer element is disposed on the image side of the second lens and is in at least partial contact with the image side surface of the second lens. The optical system satisfies -31.05<f2 / (CP1+EP12+CP2)<-22.65, wherein f2 is the effective focal length of the second lens, CP1 is the maximum thickness of the first spacer element along the optical axis, CP2 is the maximum thickness of the second spacer element along the optical axis, and EP12 is the distance from the image side surface of the first spacer element to the object side surface of the second spacer element along the optical axis. By controlling the effective focal length of the second lens element, the maximum thickness of the first spacer element along the optical axis, and the maximum thickness of the second spacer element along the optical axis, the edge thickness of the second lens can be effectively controlled, improving the ultimate process during lens production and thereby enhancing the stability of lens assembly.

[0110] In an embodiment of the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface, that is, at least one of the mirror surfaces from the object side surface of the first lens to the image side surface of the sixth lens is an aspherical mirror surface. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After adopting an aspherical lens, the aberration that occurs during imaging can be eliminated as much as possible, thereby improving the imaging quality. Optionally, the object side surface and the image side surface of all lenses from the first lens to the sixth lens are aspherical mirror surfaces.

[0111] In an exemplary embodiment, the optical system may further include a filter for correcting color deviation and / or a protective glass for protecting a photosensitive element located on the imaging surface.

[0112] According to the above-mentioned embodiment of the present application, the optical system may adopt multiple lenses, such as the six lenses mentioned above. The six-piece optical system provided by the present application adopts a small head lens architecture to ensure that the aperture of the first lens is small while achieving the performance characteristics of small distortion and small field curvature, while ensuring a high relative illumination, which is beneficial for the back-end algorithm to process the image. The six-piece optical system provided by the present application has good assembly stability, which can better meet specific photography requirements while also bringing advantages in terms of volume, weight and cost. However, it should be understood by those skilled in the art that, without departing from the technical solution claimed for protection in this application, the number of lenses constituting the optical system can be changed to obtain the various results and advantages described in this specification. For example, although six lenses are described as an example in the embodiment, the optical system is not limited to including six lenses. If necessary, the optical system may also include other numbers of lenses.

[0113] The following further describes a specific embodiment of the optical system applicable to the above-mentioned embodiment with reference to the accompanying drawings. Figures 2A to 3D Describe the optical system 1001 according to embodiment 1 and the optical system 1002 according to embodiment 2 of the present application; 4A to 5D Describe the optical system 2001 according to embodiment 3 of the present application and the optical system 2002 according to embodiment 4; 6A to 7D Describe the optical system 3001 according to embodiment 5 of the present application and the optical system 3002 according to embodiment 6; 8A to 9D An optical system 4001 according to Example 7 and an optical system 4002 according to Example 8 of the present application are described.

[0114] Example 1

[0115] Figure 2A FIG. 1 shows a schematic structural diagram of an optical system 1001 according to Example 1 of the present application. Figure 2A As shown, the optical system 1001 includes a lens barrel P0, a lens group, and a spacer element group.

[0116] like Figure 2A As shown, the lens group of optical system 1001 includes, from object side to image side, 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 an object-side surface S1 and an image-side surface S2. The second lens E2 has an object-side surface S3 and an image-side surface S4. The third lens E3 has an object-side surface S5 and an image-side surface S6. The fourth lens E4 has an object-side surface S7 and an image-side surface S8. The fifth lens E5 has an object-side surface S9 and an image-side surface S10. The sixth lens E6 has an object-side surface S11 and an image-side surface S12.

[0117] Optical system 1001 also includes a filter (not shown) for correcting chromatic aberration. The filter has an object-side surface S13 and an image-side surface S14. Optical system 1001 also includes a stop STO (not shown) disposed on the object side of the first lens. Light from the object sequentially passes through surfaces S1 to S14 and is ultimately imaged on an imaging surface S15 (not shown).

[0118] Table 2 shows basic parameters of the lens group of the optical system 1001 of Example 1, wherein the units of curvature radius, thickness / distance and effective focal length are all millimeters (mm).

[0119]

[0120] Table 2

[0121] In Example 1, the object-side surface and the image-side surface of any lens among the first lens E1 to the sixth lens E6 are both aspherical surfaces. The surface shape of each aspherical lens can be defined by, but is not limited to, the following aspherical surface formula:

[0122]

[0123] Wherein, x is the distance vector height of the aspheric surface from the vertex of the aspheric surface at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 2 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Tables 3-1 and 3-2 give the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A30, A31, A32, A33, A34, A35, A36, A37, A38, A 10 、A 12 、A 14 、A 16 、A 18 、A 20 、A 22 、A 24 、A 26 、A 28 and A 30 .

[0124] Face number A4 A6 A8 A10 A12 A14 A16 S1 4.2993E-03 6.5504E-04 -2.7973E-05 -2.5022E-05 2.5626E-05 2.9685E-05 6.9668E-06 S2 -7.9703E-04 9.8588E-04 1.1814E-04 4.1423E-05 1.9162E-05 1.3581E-05 7.2400E-06 S3 -9.3899E-03 1.4107E-03 5.1610E-05 1.7293E-05 -1.4402E-07 -3.7391E-07 -1.4913E-06 S4 -8.7966E-03 1.7965E-03 -5.0106E-05 6.5974E-06 7.1844E-06 5.6158E-06 7.7269E-06 S5 -1.1210E-02 1.8709E-03 5.5486E-06 -1.5870E-06 1.0729E-05 1.9705E-06 8.0418E-06 S6 -3.3277E-02 3.5977E-04 1.0576E-04 -9.0829E-06 3.9866E-05 2.2168E-06 3.4992E-06 S7 -1.1743E-01 -7.1783E-03 -3.6826E-04 -6.2129E-04 1.2129E-04 8.6924E-05 2.7296E-05 S8 -8.1105E-02 4.6656E-03 4.5608E-03 -1.9085E-03 2.5787E-04 8.1366E-05 -4.6806E-05 S9 1.7974E-02 -1.8922E-02 8.1056E-03 -1.0848E-03 1.0412E-04 3.1108E-05 4.2156E-05 S10 2.1915E-01 3.6607E-02 2.0530E-02 5.1697E-03 2.3786E-03 5.7116E-04 3.6690E-04 S11 -2.4047E+00 5.6437E-01 -1.5543E-01 3.8225E-02 -1.3612E-02 1.0256E-02 -5.8883E-03 S12 -3.9456E+00 6.3463E-01 -1.9562E-01 3.7058E-02 1.2032E-02 1.4956E-02 -1.6768E-02

[0125] Table 3-1

[0126] Face number A18 A20 A22 A24 A26 A28 A30 S1 -5.6525E-06 -4.9756E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S2 2.4246E-06 -4.9838E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S3 -2.1801E-06 -1.4223E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S4 4.3411E-06 1.7990E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 4.1125E-06 2.3974E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S6 1.8123E-06 1.3647E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S7 3.4386E-06 5.0423E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S8 -4.0452E-05 1.2736E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S9 -2.0031E-05 -2.4595E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 1.3491E-04 5.9718E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 1.5540E-03 -1.1701E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S12 -1.0571E-03 1.8111E-03 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0127] Table 3-2

[0128] like Figure 2AAs shown, the optical system 1001 further includes eight spacers, namely a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a fifth auxiliary spacer P5b, a fifth secondary auxiliary spacer P5c, and a sixth spacer P6. The first spacer P1 is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens; the second spacer P2 is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens; and the third spacer P3 is positioned on the image side of the third lens and is in at least partial contact with the image side surface of the third lens. The fourth spacer element P4 is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; the fifth spacer element P5 is placed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; the fifth auxiliary spacer element P5b is placed on the image side of the fifth spacer element and is in at least partial contact with the image side surface of the fifth spacer element; the fifth auxiliary spacer element P5c is placed on the image side of the fifth auxiliary spacer element and is in at least partial contact with the image side surface of the fifth auxiliary spacer element; and the sixth spacer element P6 is placed on the image side of the sixth lens and is in at least partial contact with the image side surface of the sixth lens.

[0129] Table 4 shows the parameters of the spacer element of the optical system 1001. The units of each parameter in Table 4 are millimeters (mm).

[0130] parameter d1s d1m D1s D1m d2m D2s d3s d4s d4m D5s Numerical 0.844 0.888 1.842 1.842 0.970 2.630 1.152 1.521 1.571 3.833 parameter D5m D0m EP01 EP12 EP23 EP34 EP45 CP1 CP2 d2s Numerical 4.025 5.374 0.683 0.322 0.323 0.358 0.647 0.022 0.022 0.926

[0131] Table 4

[0132] Example 2

[0133] Figure 2B FIG2 is a schematic structural diagram of an optical system 1002 according to Embodiment 2 of the present application. In this embodiment, for the sake of brevity, some descriptions similar to those in Embodiment 1 will be omitted.

[0134] like Figure 2B As shown, optical system 1002 includes a lens barrel P0, a lens group, and a spacer element group. The lens group of optical system 1002 is identical to the lens group of optical system 1001 in Example 1 and will not be described in detail. Optical system 1002 also includes a filter (not shown) for correcting chromatic aberration, the filter having an object-side surface S13 and an image-side surface S14. Optical system 1001 also includes a stop STO (not shown) disposed on the object side of the first lens. Light from the object sequentially passes through each surface S1 to S14 and is ultimately imaged on an imaging surface S15 (not shown). The basic parameters of optical system 1002 are detailed in Tables 2 to 3-2.

[0135] like Figure 2BAs shown, the optical system 1002 further includes eight spacers, namely a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a fifth auxiliary spacer P5b, a fifth secondary auxiliary spacer P5c, and a sixth spacer P6. The first spacer P1 is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens; the second spacer P2 is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens; and the third spacer P3 is positioned on the image side of the third lens and is in at least partial contact with the image side surface of the third lens. The fourth spacer element P4 is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; the fifth spacer element P5 is placed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; the fifth auxiliary spacer element P5b is placed on the image side of the fifth spacer element and is in at least partial contact with the image side surface of the fifth spacer element; the fifth auxiliary spacer element P5c is placed on the image side of the fifth auxiliary spacer element and is in at least partial contact with the image side surface of the fifth auxiliary spacer element; and the sixth spacer element P6 is placed on the image side of the sixth lens and is in at least partial contact with the image side surface of the sixth lens.

[0136] Table 5 shows the parameters of the spacer element of the optical system 1002. The units of each parameter in Table 5 are millimeters (mm).

[0137] parameter d1s d1m D1s D1m d2m D2s d3s d4s d4m D5s Numerical 0.841 0.885 2.447 2.447 0.970 2.630 1.152 1.521 1.571 4.096 parameter D5m D0m EP01 EP12 EP23 EP34 EP45 CP1 CP2 d2s Numerical 4.096 5.374 0.692 0.313 0.323 0.358 0.647 0.022 0.022 0.926

[0138] Table 5

[0139] Figure 3A The axial chromatic aberration curves of the optical system 1001 of Example 1 and the optical system 1002 of Example 2 are shown, which indicate the deviation of the convergence point of light rays of different wavelengths after passing through the lens. Figure 3B Astigmatism curves of the optical system 1001 of Example 1 and the optical system 1002 of Example 2 are shown, indicating meridional field curvature and sagittal field curvature. Figure 3C Distortion curves of the optical system 1001 of Example 1 and the optical system 1002 of Example 2 are shown, which represent the distortion magnitude values corresponding to different image heights. Figure 3D The chromatic aberration curves of the optical system 1001 of Example 1 and the optical system 1002 of Example 2 are shown, which represent the deviation of the different image heights on the imaging surface after the light passes through the lens. Figures 3A to 3D It can be seen that the optical system 1001 and the optical system 1002 of Example 2 can achieve good imaging quality.

[0140] Example 3

[0141] Figure 4A FIG. 2 shows a schematic structural diagram of an optical system 2001 according to Example 3 of the present application. Figure 4A As shown, the optical system 2001 includes a lens barrel P0, a lens group, and a spacer element group.

[0142] like Figure 4A As shown, the lens group of optical system 2001 includes, from object side to image side, 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 an object-side surface S1 and an image-side surface S2. The second lens E2 has an object-side surface S3 and an image-side surface S4. The third lens E3 has an object-side surface S5 and an image-side surface S6. The fourth lens E4 has an object-side surface S7 and an image-side surface S8. The fifth lens E5 has an object-side surface S9 and an image-side surface S10. The sixth lens E6 has an object-side surface S11 and an image-side surface S12.

[0143] Optical system 2001 also includes a filter (not shown) for correcting chromatic aberration. The filter has an object-side surface S13 and an image-side surface S14. Optical system 2001 also includes a stop STO (not shown) disposed on the object side of the first lens. Light from the object sequentially passes through surfaces S1 to S14 and is ultimately imaged on an imaging surface S15 (not shown).

[0144] Table 6 shows the basic parameters of the lens assembly of optical system 2001 in Example 3, where the units of curvature radius, thickness / distance, and effective focal length are all in millimeters (mm). Tables 7-1 and 7-2 show the high-order coefficients of the various aspheric mirror surfaces that can be used in Example 3, where the surface shape of each aspheric surface can be defined by formula (1) given in Example 1 above.

[0145]

[0146] Table 6

[0147] Face number A4 A6 A8 A10 A12 A14 A16 S1 3.3289E-04 3.6383E-05 2.1411E-06 5.7392E-07 3.1806E-08 9.8728E-08 -8.3312E-08 S2 -8.7185E-04 4.8875E-04 3.1124E-05 6.3427E-06 1.0788E-06 -4.9566E-07 -2.3148E-07 S3 -7.3307E-03 1.0808E-03 3.9223E-05 5.7585E-06 -1.3189E-06 -2.8443E-06 -1.1688E-07 S4 -9.5725E-03 1.5262E-03 -6.0813E-06 -4.1866E-06 -3.6253E-06 -3.7724E-06 -7.1449E-08 S5 -7.5739E-03 1.6421E-03 5.8044E-05 -9.0854E-06 -5.5960E-06 -5.6313E-06 -1.1065E-07 S6 -3.4848E-02 9.3666E-04 3.6166E-04 7.2265E-05 4.3173E-05 6.7240E-06 -2.0309E-06 S7 -1.0602E-01 -6.4154E-03 -4.0280E-04 -4.1918E-04 4.4792E-05 7.1928E-05 3.9514E-05 S8 -7.6446E-02 7.2863E-03 4.6801E-03 -1.9782E-03 1.0490E-04 8.4430E-05 -1.9699E-05 S9 -5.5565E-02 -2.6317E-02 1.1118E-02 -2.7033E-03 -5.3758E-05 -6.5812E-04 -6.0385E-04 S10 8.8935E-02 7.0287E-03 1.1218E-02 -8.8153E-04 -2.4103E-03 -1.7315E-03 -8.1929E-04 S11 -1.5194E+00 3.9124E-01 -1.6690E-01 4.7529E-02 -9.4872E-03 1.2999E-03 -2.7559E-03 S12 -1.3314E+00 3.1554E-01 -6.8608E-02 1.7075E-02 -7.1840E-03 3.4677E-03 -1.3654E-03

[0148] Table 7-1

[0149]

[0150]

[0151] Table 7-2

[0152] like Figure 4AAs shown, the optical system 2001 further includes eight spacers, namely a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a fifth auxiliary spacer P5b, a fifth secondary auxiliary spacer P5c, and a sixth spacer P6. The first spacer P1 is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens; the second spacer P2 is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens; and the third spacer P3 is positioned on the image side of the third lens and is in at least partial contact with the image side surface of the third lens. The fourth spacer element P4 is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; the fifth spacer element P5 is placed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; the fifth auxiliary spacer element P5b is placed on the image side of the fifth spacer element and is in at least partial contact with the image side surface of the fifth spacer element; the fifth auxiliary spacer element P5c is placed on the image side of the fifth auxiliary spacer element and is in at least partial contact with the image side surface of the fifth auxiliary spacer element; and the sixth spacer element P6 is placed on the image side of the sixth lens and is in at least partial contact with the image side surface of the sixth lens.

[0153] Table 8 shows the parameters of the spacer element of the optical system 2001. The units of each parameter in Table 8 are millimeters (mm).

[0154] parameter d1s d1m D1s D1m d2m D2s d3s d4s d4m D5s Numerical 0.908 0.952 2.524 2.524 0.998 2.636 1.096 1.780 1.851 3.384 parameter D5m D0m EP01 EP12 EP23 EP34 EP45 CP1 CP2 d2s Numerical 3.827 5.372 0.675 0.304 0.320 0.346 0.428 0.022 0.022 0.954

[0155] Table 8

[0156] Example 4

[0157] Figure 4B FIG2 shows a schematic structural diagram of an optical system 2002 according to Embodiment 4 of the present application. In this embodiment, for the sake of brevity, some descriptions similar to those in Embodiment 3 will be omitted.

[0158] like Figure 4B As shown, optical system 2002 includes a lens barrel P0, a lens group, and a spacer element group. The lens group of optical system 2002 is identical to the lens group of optical system 2001 in Example 3 and will not be described in detail. Optical system 2002 also includes a filter (not shown) for correcting chromatic aberration, the filter having an object-side surface S13 and an image-side surface S14. Optical system 1001 also includes a stop STO (not shown) disposed on the object side of the first lens. Light from the object sequentially passes through each surface S1 to S14 and is ultimately imaged on an imaging surface S15 (not shown). The basic parameters of optical system 2002 are detailed in Tables 6 to 7-2.

[0159] like Figure 4BAs shown, the optical system 2002 further includes eight spacers, namely a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a fifth auxiliary spacer P5b, a fifth secondary auxiliary spacer P5c, and a sixth spacer P6. The first spacer P1 is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens; the second spacer P2 is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens; and the third spacer P3 is positioned on the image side of the third lens and is in at least partial contact with the image side surface of the third lens. The fourth spacer element P4 is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; the fifth spacer element P5 is placed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; the fifth auxiliary spacer element P5b is placed on the image side of the fifth spacer element and is in at least partial contact with the image side surface of the fifth spacer element; the fifth auxiliary spacer element P5c is placed on the image side of the fifth auxiliary spacer element and is in at least partial contact with the image side surface of the fifth auxiliary spacer element; and the sixth spacer element P6 is placed on the image side of the sixth lens and is in at least partial contact with the image side surface of the sixth lens.

[0160] Table 9 shows the parameters of the spacer element of the optical system 2002. The units of each parameter in Table 9 are millimeters (mm).

[0161] parameter d1s d1m D1s D1m d2m D2s d3s d4s d4m D5s Numerical 0.908 0.952 2.524 2.524 0.998 2.636 1.096 1.463 1.415 3.960 parameter D5m D0m EP01 EP12 EP23 EP34 EP45 CP1 CP2 d2s Numerical 3.960 5.372 0.675 0.304 0.320 0.354 0.470 0.022 0.022 0.954

[0162] Table 9

[0163] Figure 5A The axial chromatic aberration curves of the optical system 2001 of Example 3 and the optical system 2002 of Example 4 are shown, which indicate the deviation of the convergence point of light rays of different wavelengths passing through the lens. Figure 5B Astigmatism curves of the optical system 2001 of Example 3 and the optical system 2002 of Example 4 are shown, indicating meridional field curvature and sagittal field curvature. Figure 5C Distortion curves of the optical system 2001 of Example 3 and the optical system 2002 of Example 4 are shown, which represent the distortion magnitude values corresponding to different image heights. Figure 5D The chromatic aberration curves of the optical system 2001 of Example 3 and the optical system 2002 of Example 4 are shown, which represent the deviation of the different image heights on the imaging surface after the light passes through the lens. 5A to 5D It can be seen that the optical system 2001 of Example 3 and the optical system 2002 of Example 4 can achieve good imaging quality.

[0164] Example 5

[0165] Figure 6A FIG. 3 shows a schematic structural diagram of an optical system 3001 according to Example 5 of the present application. Figure 6A As shown, the optical system 3001 includes a lens barrel P0, a lens group, and a spacer element group.

[0166] like Figure 6A As shown, the lens group of optical system 3001 includes, from object side to image side, 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 an object-side surface S1 and an image-side surface S2. The second lens E2 has an object-side surface S3 and an image-side surface S4. The third lens E3 has an object-side surface S5 and an image-side surface S6. The fourth lens E4 has an object-side surface S7 and an image-side surface S8. The fifth lens E5 has an object-side surface S9 and an image-side surface S10. The sixth lens E6 has an object-side surface S11 and an image-side surface S12.

[0167] Optical system 2001 also includes a filter (not shown) for correcting chromatic aberration. The filter has an object-side surface S13 and an image-side surface S14. Optical system 2001 also includes a stop STO (not shown) disposed on the object side of the first lens. Light from the object sequentially passes through surfaces S1 to S14 and is ultimately imaged on an imaging surface S15 (not shown).

[0168] Table 10 shows the basic parameters of the lens assembly of optical system 3001 in Example 5, where the units of curvature radius, thickness / distance, and effective focal length are all in millimeters (mm). Tables 11-1 and 11-2 show the high-order coefficients of the various aspheric mirror surfaces that can be used in Example 5, where the surface shape of each aspheric surface can be defined by formula (1) given in Example 1 above.

[0169]

[0170]

[0171] Table 10

[0172] Face number A4 A6 A8 A10 A12 A14 A16 S1 2.0697E-03 2.6300E-04 2.8701E-05 2.7175E-06 -1.0932E-06 -3.8927E-07 4.2198E-07 S2 1.4616E-03 1.3683E-03 7.0850E-05 1.0951E-05 -1.2153E-05 -1.7119E-06 1.6531E-06 S3 -1.1277E-02 1.8843E-03 -5.8108E-05 1.0161E-05 -2.1242E-05 -3.0599E-06 2.8615E-06 S4 -1.2126E-02 3.7909E-03 -4.0922E-05 1.1863E-04 -4.4210E-06 -5.7100E-06 1.7692E-06 S5 -1.3497E-02 4.3446E-03 1.4623E-04 2.0477E-04 3.3790E-05 -1.0293E-05 2.9245E-07 S6 -3.6936E-02 1.1836E-03 -4.0647E-05 2.8963E-05 8.7814E-05 9.9271E-06 4.7790E-06 S7 -8.8831E-02 -4.4998E-03 4.7508E-04 -5.3277E-04 1.0564E-06 6.9110E-06 1.7814E-06 S8 -3.4513E-02 -5.9905E-03 4.0434E-03 -8.3174E-04 6.8852E-05 2.3083E-06 -2.8043E-06 S9 4.1051E-02 -2.3272E-02 4.7179E-03 -5.9954E-04 6.7368E-05 -9.7560E-06 2.2462E-05 S10 5.2326E-02 3.6402E-03 1.0535E-03 1.0211E-04 7.1082E-05 3.8884E-05 7.1838E-05 S11 -6.8306E-01 6.9837E-02 -1.5620E-02 3.2683E-03 -5.5473E-04 2.4262E-04 5.1400E-05 S12 -5.1374E-01 2.0473E-02 5.7761E-04 -6.2410E-04 7.5517E-04 -1.3407E-04 1.8139E-04

[0173] Table 11-1

[0174] Face number A18 A20 A22 A24 A26 A28 A30 S1 7.3427E-07 -4.0290E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S2 1.0489E-06 -7.0657E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S3 4.0732E-07 -7.2130E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S4 -9.4390E-08 -8.0864E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 -6.1482E-07 -4.5754E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S6 1.6775E-06 3.7238E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S7 5.4611E-07 1.1973E-06 5.7436E-08 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S8 1.2364E-06 4.3211E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S9 -3.6623E-06 1.2091E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 -2.6596E-05 3.9901E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 -1.2258E-04 2.8273E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S12 -2.2642E-04 1.4280E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0175] Table 11-2

[0176] like Figure 6AAs shown, the optical system 3001 further includes eight spacers, namely a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a fifth auxiliary spacer P5b, a fifth secondary auxiliary spacer P5c, and a sixth spacer P6. The first spacer P1 is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens; the second spacer P2 is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens; and the third spacer P3 is positioned on the image side of the third lens and is in at least partial contact with the image side surface of the third lens. The fourth spacer element P4 is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; the fifth spacer element P5 is placed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; the fifth auxiliary spacer element P5b is placed on the image side of the fifth spacer element and is in at least partial contact with the image side surface of the fifth spacer element; the fifth auxiliary spacer element P5c is placed on the image side of the fifth auxiliary spacer element and is in at least partial contact with the image side surface of the fifth auxiliary spacer element; and the sixth spacer element P6 is placed on the image side of the sixth lens and is in at least partial contact with the image side surface of the sixth lens.

[0177] Table 12 shows the parameters of the spacer element of the optical system 3001. The units of each parameter in Table 12 are millimeters (mm).

[0178] parameter d1s d1m D1s D1m d2m D2s d3s d4s d4m D5s Numerical 1.009 1.053 1.890 1.890 1.111 2.002 1.187 1.455 1.499 3.623 parameter D5m D0m EP01 EP12 EP23 EP34 EP45 CP1 CP2 d2s Numerical 3.814 5.405 0.616 0.315 0.366 0.419 0.661 0.022 0.022 1.067

[0179] Table 12

[0180] Example 6

[0181] Figure 6B FIG2 shows a schematic structural diagram of an optical system 3002 according to Example 6 of the present application. In this embodiment, for the sake of brevity, some descriptions similar to those in Example 5 will be omitted.

[0182] like Figure 6B As shown, optical system 3002 includes a lens barrel P0, a lens group, and a spacer element group. The lens group of optical system 3002 is identical to the lens group of optical system 3001 in Example 5 and will not be described in detail. Optical system 3002 also includes a filter (not shown) for correcting chromatic aberration, the filter having an object-side surface S13 and an image-side surface S14. Optical system 1001 also includes a stop STO (not shown) disposed on the object side of the first lens. Light from the object sequentially passes through each surface S1 to S14 and is ultimately imaged on an imaging surface S15 (not shown). The basic parameters of optical system 3002 are detailed in Tables 10 to 11-2.

[0183] like Figure 6BAs shown, the optical system 3002 further includes eight spacers, namely a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a fifth auxiliary spacer P5b, a fifth secondary auxiliary spacer P5c, and a sixth spacer P6. The first spacer P1 is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens; the second spacer P2 is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens; and the third spacer P3 is positioned on the image side of the third lens and is in at least partial contact with the image side surface of the third lens. The fourth spacer element P4 is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; the fifth spacer element P5 is placed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; the fifth auxiliary spacer element P5b is placed on the image side of the fifth spacer element and is in at least partial contact with the image side surface of the fifth spacer element; the fifth auxiliary spacer element P5c is placed on the image side of the fifth auxiliary spacer element and is in at least partial contact with the image side surface of the fifth auxiliary spacer element; and the sixth spacer element P6 is placed on the image side of the sixth lens and is in at least partial contact with the image side surface of the sixth lens.

[0184] Table 13 shows the parameters of the spacer element of the optical system 3002. The units of each parameter in Table 13 are millimeters (mm).

[0185] parameter d1s d1m D1s D1m d2m D2s d3s d4s d4m D5s Numerical 1.011 1.055 2.506 2.506 1.122 2.602 1.187 1.455 1.499 3.623 parameter D5m D0m EP01 EP12 EP23 EP34 EP45 CP1 CP2 d2s Numerical 3.859 5.405 0.621 0.324 0.353 0.422 0.661 0.022 0.022 1.078

[0186] Table 13

[0187] Figure 7A The axial chromatic aberration curves of the optical system 3001 of Example 5 and the optical system 3002 of Example 6 are shown, which indicate the deviation of the convergence point of light rays of different wavelengths after passing through the lens. Figure 7B Astigmatism curves of the optical system 3001 of Example 5 and the optical system 3002 of Example 6 are shown, indicating meridional field curvature and sagittal field curvature. Figure 7C Distortion curves of the optical system 3001 of Example 5 and the optical system 3002 of Example 6 are shown, which represent the distortion magnitude values corresponding to different image heights. Figure 7D The chromatic aberration curves of the optical system 3001 of Example 5 and the optical system 3002 of Example 6 are shown, which represent the deviation of the different image heights on the imaging surface after the light passes through the lens. 7A to 7D It can be seen that the optical system 3001 of Example 5 and the optical system 3002 of Example 6 can achieve good imaging quality.

[0188] Example 7

[0189] Figure 8AFIG. 4 shows a schematic structural diagram of an optical system 4001 according to Example 7 of the present application. Figure 8A As shown, the optical system 4001 includes a lens barrel P0, a lens group, and a spacer element group.

[0190] like Figure 8A As shown, the lens group of optical system 4001 includes, from object side to image side, 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 an object-side surface S1 and an image-side surface S2. The second lens E2 has an object-side surface S3 and an image-side surface S4. The third lens E3 has an object-side surface S5 and an image-side surface S6. The fourth lens E4 has an object-side surface S7 and an image-side surface S8. The fifth lens E5 has an object-side surface S9 and an image-side surface S10. The sixth lens E6 has an object-side surface S11 and an image-side surface S12.

[0191] Optical system 2001 also includes a filter (not shown) for correcting chromatic aberration. The filter has an object-side surface S13 and an image-side surface S14. Optical system 2001 also includes a stop STO (not shown) disposed on the object side of the first lens. Light from the object sequentially passes through surfaces S1 to S14 and is ultimately imaged on an imaging surface S15 (not shown).

[0192] Table 14 shows the basic parameters of the lens assembly of optical system 4001 in Example 7, where the units of curvature radius, thickness / distance, and effective focal length are all in millimeters (mm). Tables 15-1 and 15-2 show the high-order coefficients of the various aspheric mirror surfaces that can be used in Example 7, where the surface shape of each aspheric surface can be defined by formula (1) given in Example 1 above.

[0193]

[0194] Table 14

[0195] Face number A4 A6 A8 A10 A12 A14 A16 S1 2.5357E-03 3.9749E-04 -1.4542E-05 2.2267E-06 2.8832E-05 2.2035E-05 2.8925E-06 S2 -2.3250E-03 9.9967E-04 1.4530E-04 4.7153E-05 2.0138E-05 1.3839E-05 5.1548E-06 S3 -8.3952E-03 1.2514E-03 9.9949E-05 1.4200E-05 -4.4360E-06 -1.2834E-06 -2.4324E-06 S4 -6.6759E-03 1.4713E-03 -3.2836E-05 1.5630E-05 5.9209E-06 1.0538E-05 7.0487E-06 S5 -6.4042E-03 1.4314E-03 -2.2877E-05 1.4187E-05 5.5025E-06 7.7227E-06 8.7910E-06 S6 -2.8900E-02 -8.9558E-05 1.1265E-04 2.8811E-05 4.2087E-05 -6.4566E-07 2.8338E-06 S7 -1.1508E-01 -7.7056E-03 -1.8764E-04 -6.1582E-04 1.1179E-04 7.8827E-05 2.9358E-05 S8 -6.5889E-02 3.9914E-03 4.5939E-03 -1.9094E-03 2.6466E-04 6.4648E-05 -5.7215E-05 S9 4.2682E-02 -2.2705E-02 9.5225E-03 -1.6212E-03 4.0366E-04 8.6248E-05 -3.1609E-05 S10 -8.5196E-03 -8.7936E-03 9.1557E-03 -1.3806E-03 6.6241E-04 -1.2561E-04 -7.9914E-05 S11 -2.3026E+00 6.3152E-01 -2.0636E-01 6.2496E-02 -1.7354E-02 5.1715E-03 -1.7446E-03 S12 -4.4813E+00 8.0284E-01 -2.7810E-01 9.5939E-02 -2.1523E-02 1.8463E-02 -7.3883E-03

[0196] Table 15-1

[0197]

[0198]

[0199] Table 15-2

[0200] like Figure 8AAs shown, the optical system 4001 further includes eight spacers, namely a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a fifth auxiliary spacer P5b, a fifth secondary auxiliary spacer P5c, and a sixth spacer P6. The first spacer P1 is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens; the second spacer P2 is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens; and the third spacer P3 is positioned on the image side of the third lens and is in at least partial contact with the image side surface of the third lens. The fourth spacer element P4 is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; the fifth spacer element P5 is placed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; the fifth auxiliary spacer element P5b is placed on the image side of the fifth spacer element and is in at least partial contact with the image side surface of the fifth spacer element; the fifth auxiliary spacer element P5c is placed on the image side of the fifth auxiliary spacer element and is in at least partial contact with the image side surface of the fifth auxiliary spacer element; and the sixth spacer element P6 is placed on the image side of the sixth lens and is in at least partial contact with the image side surface of the sixth lens.

[0201] Table 16 shows the parameters of the spacer element of the optical system 4001. The units of each parameter in Table 16 are millimeters (mm).

[0202] parameter d1s d1m D1s D1m d2m D2s d3s d4s d4m D5s Numerical 0.781 0.825 2.179 2.179 0.953 2.350 1.505 1.920 1.964 4.246 parameter D5m D0m EP01 EP12 EP23 EP34 EP45 CP1 CP2 d2s Numerical 4.649 6.137 0.527 0.299 0.263 0.251 0.514 0.022 0.029 1.012

[0203] Table 16

[0204] Example 8

[0205] Figure 8B FIG2 shows a schematic structural diagram of an optical system 4002 according to Example 8 of the present application. In this embodiment, for the sake of brevity, some descriptions similar to those in Example 7 will be omitted.

[0206] like Figure 8B As shown, optical system 4002 includes a lens barrel P0, a lens group, and a spacer element group. The lens group of optical system 4002 is identical to the lens group of optical system 4001 in Example 7 and will not be described in detail. Optical system 4002 also includes a filter (not shown) for correcting chromatic aberration, the filter having an object-side surface S13 and an image-side surface S14. Optical system 1001 also includes a stop STO (not shown) disposed on the object side of the first lens. Light from the object sequentially passes through each surface S1 to S14 and is ultimately imaged on an imaging surface S15 (not shown). The basic parameters of optical system 4002 are detailed in Tables 14 to 15-2.

[0207] like Figure 8BAs shown, the optical system 4002 further includes eight spacers, namely a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a fifth auxiliary spacer P5b, a fifth secondary auxiliary spacer P5c, and a sixth spacer P6. The first spacer P1 is positioned on the image side of the first lens and is in at least partial contact with the image side surface of the first lens; the second spacer P2 is positioned on the image side of the second lens and is in at least partial contact with the image side surface of the second lens; and the third spacer P3 is positioned on the image side of the third lens and is in at least partial contact with the image side surface of the third lens. The fourth spacer element P4 is placed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; the fifth spacer element P5 is placed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; the fifth auxiliary spacer element P5b is placed on the image side of the fifth spacer element and is in at least partial contact with the image side surface of the fifth spacer element; the fifth auxiliary spacer element P5c is placed on the image side of the fifth auxiliary spacer element and is in at least partial contact with the image side surface of the fifth auxiliary spacer element; and the sixth spacer element P6 is placed on the image side of the sixth lens and is in at least partial contact with the image side surface of the sixth lens.

[0208] Table 17 shows the parameters of the spacer element of the optical system 4002. The units of each parameter in Table 17 are millimeters (mm).

[0209] parameter d1s d1m D1s D1m d2m D2s d3s d4s d4m D5s Numerical 0.781 0.825 2.194 2.194 0.953 2.350 1.315 1.762 1.718 4.246 parameter D5m D0m EP01 EP12 EP23 EP34 EP45 CP1 CP2 d2s Numerical 4.649 6.137 0.560 0.306 0.300 0.264 0.397 0.022 0.022 0.997

[0210] Table 17

[0211] Figure 9A The axial chromatic aberration curves of the optical system 4001 of Example 7 and the optical system 4002 of Example 8 are shown, which indicate the deviation of the convergence point of light rays of different wavelengths passing through the lens. Figure 9B Astigmatism curves of the optical system 4001 of Example 7 and the optical system 4002 of Example 8 are shown, which indicate meridional field curvature and sagittal field curvature. Figure 9C Distortion curves of the optical system 4001 of Example 7 and the optical system 4002 of Example 8 are shown, which represent the distortion magnitude values corresponding to different image heights. Figure 9D The chromatic aberration curves of the optical system 4001 of Example 7 and the optical system 4002 of Example 8 are shown, which represent the deviation of the different image heights on the imaging surface after the light passes through the lens. 9A to 9D It can be seen that the optical system 4001 of Example 7 and the optical system 4002 of Example 8 can achieve good imaging quality.

[0212] In summary, the optical systems of Examples 1 to 8 satisfy the relationship shown in Table 18.

[0213] Conditional formula / Example 1 2 3 4 5 6 7 8 EP12 / T23 4.14 4.03 4.27 4.27 3.16 3.24 4.30 4.41 CT1 / (T12+CP1) 3.95 3.95 4.33 4.33 3.65 3.65 4.46 4.46 f4 / EP34 31.64 31.64 28.89 28.22 36.91 36.69 34.65 32.91 R7 / d4s -1.62 -1.62 -1.70 -2.07 -1.67 -1.67 -1.31 -1.43 f5 / (EP45+CT5) -2.54 -2.54 -4.48 -4.28 -2.21 -2.21 -3.92 -4.42 d4m / R9 -2.31 -2.31 -2.36 -1.80 -2.19 -2.19 -2.78 -2.43 f3 / (EP23+T34) 7.39 7.39 6.97 6.97 6.36 6.50 8.64 8.04 D0m / R12 2.86 2.86 3.05 3.05 1.66 1.66 4.50 4.50 f1 / EP01 5.14 5.08 4.99 4.99 5.47 5.42 7.01 6.60 (d1s+d1m) / R1 1.73 1.73 1.91 1.91 2.11 2.12 1.61 1.61 D1s / R2 1.02 1.35 1.41 1.41 1.03 1.37 1.24 1.25 <h2 style=";text-align:left;direction:ltr">(R3×D1m) / (R4×D2s) 1.00 1.33 1.43 1.43 1.40 1.43 1.27 1.28 <h2 style=";text-align:left;direction:ltr"> R5 / d2m 2.72 2.72 2.32 2.32 2.10 2.08 3.05 3.05 <h2 style=";text-align:left;direction:ltr"> R6 / d3s -18.14 -18.14 -11.27 -11.27 -30.35 -30.35 -7.53 -8.62 <h2 style=";text-align:left;direction:ltr"> f2 / (CP1+EP12+CP2) -26.00 -26.62 -23.62 -23.62 -23.24 -22.70 -31.01 -31.01 <h2 style=";text-align:left;direction:ltr"> (R10 / D5s) / (R11 / D5m) -0.96 -0.91 -0.63 -0.56 -0.80 -0.81 -0.93 -0.93

[0214] Table 18

[0215] The present application also provides an imaging device, wherein the electronic photosensitive element thereof may be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The imaging device may be a standalone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical system described above.

[0216] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An optical system, characterized in that: include: A lens barrel and a lens group and a spacer element group placed in the lens barrel, wherein: The lens group includes, in order from the object side to the image side along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens; The spacer element group includes: a first spacer element and a second spacer element, wherein the first spacer element is disposed on the image side of the first lens and is in at least partial contact with the image side surface of the first lens, and the second spacer element is disposed on the image side of the second lens and is in at least partial contact with the image side surface of the second lens; The number of lenses having optical power in the optical system is six; The optical system satisfies the following conditions: 3.6<CT1 / (T12+CP1)<4.5 and 3.12<EP12 / T23<4.45; wherein CT1 is the center thickness of the first lens on the optical axis, T12 is the air gap between the first lens and the second lens on the optical axis, CP1 is the maximum thickness of the first spacer element along the optical axis, EP12 is the distance from the image side surface of the first spacer element to the object side surface of the second spacer element along the optical axis, and T23 is the air gap between the second lens and the third lens on the optical axis.

2. The optical system according to claim 1, wherein: The spacer element group includes: a third spacer element and a fourth spacer element, wherein the third spacer element is disposed on the image side of the third lens and is in at least partial contact with the image side surface of the third lens, and the fourth spacer element is disposed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens; The optical system satisfies: 28.2<f4 / EP34<36.95, wherein f4 is the effective focal length of the fourth lens, and EP34 is the distance from the image side surface of the third spacer element to the object side surface of the fourth spacer element along the optical axis.

3. The optical system according to claim 1, wherein: The spacer element group further includes: a fourth spacer element disposed on the image side of the fourth lens and in at least partial contact with the image side surface of the fourth lens; The optical system satisfies: -2.1<R7 / d4s<-1.3, wherein R7 is the curvature radius of the object side surface of the fourth lens, and d4s is the inner diameter of the object side surface of the fourth spacer element.

4. The optical system according to claim 1, wherein: The spacer element group includes: a fourth spacer element and a fifth spacer element, wherein the fourth spacer element is disposed on the image side of the fourth lens and is in at least partial contact with the image side surface of the fourth lens, and the fifth spacer element is disposed on the image side of the fifth lens and is in at least partial contact with the image side surface of the fifth lens; The optical system satisfies the following: -4.5<f5 / (EP45+CT5)<-2.2, where f5 is the effective focal length of the fifth lens, EP45 is the distance from the image side surface of the fourth spacer element to the object side surface of the fifth spacer element along the optical axis, and CT5 is the center thickness of the fifth lens on the optical axis.

5. The optical system according to claim 1, wherein: The spacer element group further includes: a fourth spacer element disposed on the image side of the fourth lens and in at least partial contact with the image side surface of the fourth lens; The optical system satisfies: -2.8<d4m / R9≤-1.8, wherein d4m is the inner diameter of the image-side surface of the fourth spacer element, and R9 is the curvature radius of the object-side surface of the fifth lens.

6. The optical system according to claim 1, wherein: The spacer element group further includes: a third spacer element disposed on the image side of the third lens and in at least partial contact with the image side surface of the third lens; The optical system satisfies the following: 6.32<f3 / (EP23+T34)<8.68, where f3 is the effective focal length of the third lens, EP23 is the distance from the image side surface of the second spacer element to the object side surface of the third spacer element along the optical axis, and T34 is the air spacing between the third lens and the fourth lens on the optical axis.

7. The optical system according to any one of claims 1 to 6, characterized in that: The optical system satisfies the following: 1.62<D0m / R12<4.55, wherein D0m is the outer diameter of the image side end surface of the lens barrel, and R12 is the curvature radius of the image side surface of the sixth lens.

8. The optical system according to any one of claims 1 to 6, characterized in that: The optical system satisfies the following: 4.95<f1 / EP01<7.05, wherein f1 is the effective focal length of the first lens, and EP01 is the distance from the object side end surface of the lens barrel to the object side surface of the first spacer element along the optical axis.

9. The optical system according to any one of claims 1 to 6, characterized in that: The optical system satisfies: 1.6<(d1s+d1m) / R1<2.15, wherein d1s is the inner diameter of the object side surface of the first spacer element, d1m is the inner diameter of the image side surface of the first spacer element, and R1 is the curvature radius of the object side surface of the first lens.

10. The optical system according to any one of claims 1 to 6, characterized in that: The optical system satisfies the following relationship: 1.0<D1s / R2<1.45, wherein D1s is the outer diameter of the object-side surface of the first spacer element, and R2 is the curvature radius of the image-side surface of the first lens.

11. The optical system according to any one of claims 1 to 6, characterized in that: The optical system satisfies: 1.0≤(R3×D1m) / (R4×D2s)<1.45, wherein R3 is the curvature radius of the object side surface of the second lens, R4 is the curvature radius of the image side surface of the second lens, D1m is the outer diameter of the image side surface of the first spacer element, and D2s is the outer diameter of the object side surface of the second spacer element.

12. The optical system according to any one of claims 1 to 6, characterized in that: The optical system satisfies the following: 2.05<R5 / d2m<3.1, wherein R5 is the curvature radius of the object side surface of the third lens, and d2m is the inner diameter of the image side surface of the second spacer element.

13. The optical system according to any one of claims 1, 3 to 5, characterized in that: The spacer element group further includes: a third spacer element disposed on the image side of the third lens and in at least partial contact with the image side surface of the third lens; The optical system satisfies: -30.4<R6 / d3s<-7.5, wherein R6 is the curvature radius of the image side surface of the third lens, and d3s is the inner diameter of the object side surface of the third spacer element.

14. The optical system according to any one of claims 1 to 6, characterized in that: The optical system satisfies: -31.05<f2 / (CP1+EP12+CP2)<-22.65, where f2 is the effective focal length of the second lens, CP1 is the maximum thickness of the first spacer element along the optical axis, CP2 is the maximum thickness of the second spacer element along the optical axis, and EP12 is the distance from the image side surface of the first spacer element to the object side surface of the second spacer element along the optical axis.

15. The optical system according to any one of claims 1 to 3, 5 and 6, characterized in that: The spacer element group further includes: a fifth spacer element disposed on the image side of the fifth lens and in at least partial contact with the image side surface of the fifth lens; The optical system satisfies: -1.0<(R10 / D5s) / (R11 / D5m)<-0.52, wherein R10 is the curvature radius of the image side surface of the fifth lens, R11 is the curvature radius of the object side surface of the sixth lens, D5s is the outer diameter of the object side surface of the fifth spacer element, and D5m is the outer diameter of the image side surface of the fifth spacer element.

16. The optical system according to any one of claims 1 to 6, characterized in that: The optical system satisfies the following conditions: 0.75mm<d1s<1.05mm and 0.9mm<d2s<1.1mm, in, d1s is the inner diameter of the object side of the first spacer element, d2s is the inner diameter of the object side of the second spacer element.

17. The optical system according to claim 1, wherein: The object side surface of the first lens is convex, and the image side surface is concave; The object side surface of the second lens is convex, and the image side surface is concave; The object-side surface of the third lens is convex, and the image-side surface is convex; The object-side surface of the fourth lens is concave, and the image-side surface is convex; The object-side surface of the fifth lens is concave, and the image-side surface is convex; The object-side surface of the sixth lens is convex, and the image-side surface is concave.

Images