Optical imaging system

Abstract

The application discloses an optical imaging system, which comprises a lens barrel, a six-piece lens group and a spacer element group arranged in the lens barrel, the six-piece lens group comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence along an optical axis from an object side to an image side, wherein the first lens and the sixth lens have negative refractive powers, the second lens and the fifth lens have positive refractive powers, and the third lens and the fourth lens have opposite positive and negative refractive powers; the spacer element group comprises a second spacer element arranged on and in contact with an image side surface of the second lens; an effective focal length f2 of the second lens and an effective focal length f3 of the third lens satisfy 1.2<|f3| / f2<3.6; a curvature radius R3 of an object side surface of the second lens, a curvature radius R4 of an image side surface of the second lens, an inner diameter d2s of an object side surface of the second spacer element and an outer diameter D2s of the object side surface of the second spacer element satisfy -3<(R4 / R3)×(D2s / d2s)<-2.

Description

Technical Field

[0001] This application relates to the field of optical devices, specifically to a six-element optical imaging system. Background Technology

[0002] Smartphones, head-mounted devices, drones, and other electronic products are equipped with cameras to capture photos and videos, perform spatial recognition and positioning, and other functions. As electronic products are upgraded and new features are developed, the imaging requirements for these cameras are becoming increasingly demanding.

[0003] To meet the high imaging requirements of camera lenses, they are usually designed with a six-element lens structure. However, the optical power of some lenses and the spacing elements at the lens positions are prone to being poorly designed, especially the optical power of lenses near the object side and the spacing elements at the lens positions. These flaws can cause stray light to be generated at these lenses. Furthermore, if the size of the spacing elements is poorly designed, it can further cause the spacing elements to block the effective light or fail to block stray light, thus seriously affecting the imaging quality of the camera lens. Summary of the Invention

[0004] This application provides an optical imaging system that can at least solve or partially solve at least one problem or other problems existing in the prior art.

[0005] One aspect of this application provides an optical imaging system comprising a lens barrel and a six-lens group and a spacer group disposed within the lens barrel. The six-lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical axis from the object side to the image side. The first and sixth lenses have negative optical power, the second and fifth lenses have positive optical power, and the third and fourth lenses have opposite optical power attributes. The spacer group includes a second spacer element disposed on and in contact with the image side of the second lens. The effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy: 1.2 < |f3| / f2 < 3.6. The radius of curvature R3 of the object side of the second lens, the radius of curvature R4 of the image side of the second lens, the inner diameter d2s of the object side of the second spacer element, and the outer diameter D2s of the object side of the second spacer element satisfy: -3 < (R4 / R3) × (D2s / d2s) < -2.

[0006] According to an exemplary embodiment of this application, the radius of curvature R12 of the image side surface of the sixth lens, the center thickness CT6 of the sixth lens on the optical axis, the inner diameter d0m of the image side end face of the lens barrel and the outer diameter D0m of the image side end face of the lens barrel satisfy: 9.3 < (R12 / CT6) × (D0m / d0m) < 13.8.

[0007] According to an exemplary embodiment of this application, the effective focal length f2 of the second lens, the radius of curvature R4 of the image side surface of the second lens, the outer diameter D2m of the image side surface of the second spacer element, and the maximum thickness CP2 of the second spacer element satisfy: -8.5 < (f2 / R4) × (D2m / CP2) < -6.1.

[0008] According to an exemplary embodiment of this application, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the inner diameter d2m of the image side of the second spacer element, and the outer diameter D2m of the image side of the second spacer element satisfy: (d2m×D2m) / |f2×f3|<1.2.

[0009] According to an exemplary embodiment of this application, the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R2 of the image side surface of the first lens, the inner diameter d0s of the object side end face of the lens barrel, and the outer diameter D0s of the object side end face of the lens barrel satisfy: 0 < (d0s × D0s) / (R1 × R2) < 2.2.

[0010] According to an exemplary embodiment of this application, the length L of the lens barrel in the direction of the optical axis, the air gap T12 between the first and second lenses on the optical axis, the air gap T45 between the fourth and fifth lenses on the optical axis, and the air gap T56 between the fifth and sixth lenses on the optical axis satisfy: 2.6 <L / (T12+T45+T56)<3.6。

[0011] According to an exemplary embodiment of this application, the spacer element group further includes a third spacer element disposed on the image side of the third lens and in contact with the image side of the third lens, wherein the effective focal length f3 of the third lens, the effective focal length f4 of the fourth lens, the inner diameter d3s of the object side of the third spacer element and the outer diameter D3s of the object side of the third spacer element satisfy: -1.3<(d3s×D3s) / (f3×f4)<0.

[0012] According to an exemplary embodiment of this application, the spacer element group further includes a third spacer element disposed on and in contact with the image side of the third lens, wherein the radius of curvature R6 of the image side of the third lens, the radius of curvature R7 of the object side of the fourth lens, the inner diameter d3m of the image side of the third spacer element and the outer diameter D3m of the image side of the third spacer element satisfy: 1.3 < (R6 / R7) × (D3m / d3m) < 2.1.

[0013] According to an exemplary embodiment of this application, the spacer element group further includes a fourth spacer element disposed on and in contact with the image-side surface of the fourth lens, wherein the effective focal length f4 of the fourth lens, the radius of curvature R8 of the image-side surface of the fourth lens, the inner diameter d4m of the image-side surface of the fourth spacer element, and the outer diameter D4m of the image-side surface of the fourth spacer element satisfy: 0.2 < |f4 / R8| × (D4m / d4m) < 1.8.

[0014] According to an exemplary embodiment of this application, the spacer element group further includes a fourth spacer element disposed on and in contact with the image-side surface of the fourth lens, wherein the total effective focal length f of the optical imaging system, the effective focal length f5 of the fifth lens, and the outer diameter D4s of the object-side surface of the fourth spacer element satisfy: 0.5 <D4s / (f+f5)<1.1。

[0015] According to an exemplary embodiment of this application, the spacer element group further includes a fifth spacer element disposed on and in contact with the image side of the fifth lens, wherein the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the inner diameter d5s of the object side of the fifth spacer element, the outer diameter D5s of the object side of the fifth spacer element, the inner diameter d5m of the image side of the fifth spacer element, and the outer diameter D5m of the image side of the fifth spacer element satisfy: 0 < (D5s + D5m - d5s - d5m) / (f5 - f6) < 1.

[0016] According to an exemplary embodiment of this application, the spacer element group further includes a third spacer element disposed on the image-side surface of the third lens and in contact with the image-side surface of the third lens, and a fourth spacer element disposed on the image-side surface of the fourth lens and in contact with the image-side surface of the fourth lens, wherein the air gap T34 between the third and fourth lenses on the optical axis, the center thickness CT4 of the fourth lens on the optical axis, the maximum thickness CP3 of the third spacer element, and the gap EP34 between the third and fourth spacer elements along the optical axis satisfy: 1.1 < (T34 + CT4) / (CP3 + EP34) < 2.5.

[0017] According to an exemplary embodiment of this application, the spacer element group further includes a fourth spacer element disposed on and in contact with the image side of the fourth lens, and a fifth spacer element disposed on and in contact with the image side of the fifth lens, wherein the effective focal length f4 of the fourth lens, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the maximum thickness CP4 of the fourth spacer element, the maximum thickness CP5 of the fifth spacer element, and the spacing EP45 of the fourth and fifth spacer elements along the optical axis satisfy: (CP4+EP45+CP5) / |f4+f5+f6|<0.3.

[0018] According to an exemplary embodiment of this application, the spacer element group further includes a fourth spacer element disposed on and in contact with the image side of the fourth lens, and a fifth spacer element disposed on and in contact with the image side of the fifth lens, wherein the combined focal length f34 of the third and fourth lenses, the combined focal length f56 of the fifth and sixth lenses, the inner diameter d4s of the object side of the fourth spacer element, and the inner diameter d5s of the object side of the fifth spacer element satisfy: 0.4 < |f56 / f34| × (d5s / d4s) < 2.5.

[0019] According to an exemplary embodiment of this application, the spacer element group further includes a third spacer element disposed on and in contact with the image-side surface of the third lens, a fourth spacer element disposed on and in contact with the image-side surface of the fourth lens, and a fifth spacer element disposed on and in contact with the image-side surface of the fifth lens, wherein the total effective focal length f of the optical imaging system, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the maximum thickness CP4 of the fourth spacer element, and the maximum thickness CP5 of the fifth spacer element satisfy: 2.1 <f / (CP2+CP3+CP4+CP5)<5.2。

[0020] The six-element optical imaging system provided in this application, when the effective focal lengths of the second and third lenses satisfy 1.2 < |f3| / f2 < 3.6, can ensure that the principal ray in the incident light is transmitted along a predetermined path by reasonably configuring the curvature radii of the object-side and image-side surfaces of the second lens and the relationship between the inner and outer diameters of the object-side surface of the second spacer element. It can also ensure that the second spacer element effectively blocks stray light generated by the incident light at the third lens without affecting the path of the principal ray in the incident light, thereby improving the imaging quality of the optical imaging system. Attached Figure Description

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

[0022] Figure 1 A schematic diagram of the structure of the optical imaging system according to this application is shown;

[0023] Figure 2 A schematic diagram of stray light in an optical imaging system under the conditions of |f3| / f2≤1.2 or |f3| / f2≥3.6 is shown.

[0024] Figure 3 A schematic diagram of stray light in the optical imaging system under the condition 1.2 < |f3| / f2 < 3.6 is shown;

[0025] Figure 4A table illustrating the sensitivity of an optical imaging system under the conditions of |f3| / f2≤1.2 or |f3| / f2≥3.6 is shown.

[0026] Figure 5 A sensitivity diagram of the optical imaging system under the condition 1.2 < |f3| / f2 < 3.6 is shown;

[0027] Figure 6 A schematic diagram of the structure of an optical imaging system according to Embodiment 1 of this application is shown;

[0028] Figure 7 A schematic diagram of the structure of an optical imaging system according to Embodiment 2 of this application is shown;

[0029] Figure 8 A schematic diagram of the structure of an optical imaging system according to Embodiment 3 of this application is shown;

[0030] Figures 9A to 9C The on-axis chromatic aberration curves, astigmatism curves, and distortion curves of the optical imaging systems according to embodiments 1, 2, and 3 of this application are shown respectively.

[0031] Figure 10 A schematic diagram of the structure of an optical imaging system according to Embodiment 4 of this application is shown;

[0032] Figure 11 A schematic diagram of the structure of an optical imaging system according to Embodiment 5 of this application is shown;

[0033] Figure 12 A schematic diagram of the structure of an optical imaging system according to Embodiment 6 of this application is shown;

[0034] Figures 13A to 13C The on-axis chromatic aberration curves, astigmatism curves, and distortion curves of the optical imaging systems according to embodiments 4, 5, and 6 of this application are shown respectively.

[0035] Figure 14 A schematic diagram of the structure of an optical imaging system according to Embodiment 7 of this application is shown;

[0036] Figure 15 A schematic diagram of the structure of an optical imaging system according to Embodiment 8 of this application is shown;

[0037] Figure 16 A schematic diagram of the structure of an optical imaging system according to Embodiment 9 of this application is shown; and

[0038] Figures 17A to 17C The on-axis chromatic aberration curves, astigmatism curves, and distortion curves of the optical imaging systems according to embodiments 7, 8, and 9 of this application are shown respectively. Detailed Implementation

[0039] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements.

[0040] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0041] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn strictly to scale.

[0042] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0043] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising" as used in this specification indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0044] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] The features, principles and other aspects of this application are described in detail below.

[0047] The first aspect of this application provides an optical imaging system that may include a lens barrel and a six-lens group disposed within the lens barrel. The six-lens group may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical axis from the object side to the image side. Air gaps may exist between any two adjacent lenses among the first to sixth lenses. The first and sixth lenses have negative optical power, the second and fifth lenses have positive optical power, and the third and fourth lenses have opposite optical power attributes.

[0048] In an exemplary embodiment, the optical imaging system may further include a group of spacers disposed within the lens barrel. The group of spacers may include one or more of a second spacer, a third spacer, a fourth spacer, and a fifth spacer. Specifically, the second spacer is disposed on and at least partially in contact with the image-side surface of the second lens; the third spacer is disposed on and at least partially in contact with the image-side surface of the third lens; the fourth spacer is disposed on and at least partially in contact with the image-side surface of the fourth lens; and the fifth spacer is disposed on and at least partially in contact with the image-side surface of the fifth lens. Proper use of spacers can effectively mitigate stray light risks, reduce interference with image quality, and thus improve the imaging quality of the optical imaging system.

[0049] In an exemplary embodiment, the effective focal length f2 of the second lens and the effective focal length f3 of the third lens can satisfy: 1.2 < |f3| / f2 < 3.6, and the radius of curvature R3 of the object-side surface of the second lens, the radius of curvature R4 of the image-side surface of the second lens, the inner diameter d2s of the object-side surface of the second spacer element, and the outer diameter D2s of the object-side surface of the second spacer element can satisfy: -3 < (R4 / R3) × (D2s / d2s) < -2. When the effective focal lengths of the second and third lenses satisfy 1.2 < |f3| / f2 < 3.6, a reasonable configuration of the relationships between the radii of curvature of the object-side and image-side surfaces of the second lens and the inner and outer diameters of the object-side surface of the second spacer element can ensure that the principal ray in the incident light is transmitted along a predetermined path, and that the second spacer element effectively blocks stray light generated at the third lens without affecting the path of the principal ray in the incident light, thereby improving the imaging quality of the optical imaging system. Figure 2 A schematic diagram of stray light in an optical imaging system under the conditions of |f3| / f2≤1.2 or |f3| / f2≥3.6 is shown. Figure 3 A schematic diagram of stray light in the optical imaging system under the condition 1.2 < |f3| / f2 < 3.6 is shown. Figure 2 and Figure 3As can be seen, by making the optical imaging system satisfy 1.2<|f3| / f2<3.6, the stray light of the optical imaging system can be significantly reduced.

[0050] In an exemplary embodiment, the radius of curvature R12 of the image-side surface of the sixth lens, the center thickness CT6 of the sixth lens on the optical axis, and the inner diameter d0m and outer diameter D0m of the image-side end face of the lens barrel can satisfy: 9.3 < (R12 / CT6) × (D0m / d0m) < 13.8. By rationally configuring the relationship between the radius of curvature of the image-side surface of the sixth lens, the center thickness of the sixth lens on the optical axis, and the inner and outer diameters of the image-side end face of the lens barrel, not only can the manufacturability of the sixth lens be improved, but also the radial dimension of the sixth lens and the total optical length of the optical imaging system can be reduced, thereby limiting the overall size of the optical imaging system.

[0051] In an exemplary embodiment, the effective focal length f2 of the second lens and the effective focal length f3 of the third lens can satisfy: 1.2 < |f3| / f2 < 3.6. The effective focal length f2 of the second lens, the radius of curvature R4 of the image-side surface of the second lens, the outer diameter D2m of the image-side surface of the second spacer element, and the maximum thickness CP2 of the second spacer element satisfy: -8.5 < (f2 / R4) × (D2m / CP2) < -6.1. When the effective focal lengths of the second and third lenses satisfy 1.2 < |f3| / f2 < 3.6, by rationally configuring the relationships between the effective focal length of the second lens, the radius of curvature of the image-side surface of the second lens, the outer diameter of the image-side surface of the second spacer element, and the maximum thickness of the second spacer element, the deflection angle of the edge field of view in the second lens can be adjusted, ensuring that the principal ray in the incident light propagates along a predetermined path, effectively reducing the sensitivity of the second and third lenses, and improving the performance of the optical imaging system. Figure 4 A table illustrating the sensitivity of an optical imaging system under the conditions of |f3| / f2≤1.2 or |f3| / f2≥3.6 is shown. Figure 5 A sensitivity table for the optical imaging system under the condition 1.2 < |f3| / f2 < 3.6 is shown. Figure 4 and Figure 5 As can be seen, by making the optical imaging system satisfy 1.2<|f3| / f2<3.6, the sensitivity of the optical imaging system can be significantly reduced.

[0052] In an exemplary embodiment, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the inner diameter d2m of the image side surface of the second spacer element, and the outer diameter D2m of the image side surface of the second spacer element may satisfy: (d2m × D2m) / |f2 × f3| < 1.2. By reasonably configuring the mutual relationship among the effective focal length of the second lens, the effective focal length of the third lens, the inner diameter of the image side surface of the second spacer element, and the outer diameter of the image side surface of the second spacer element, the second spacer element can effectively block the stray light generated by the incident light in the second lens without affecting the main light path in the incident light.

[0053] In an exemplary embodiment, the curvature radius R1 of the object side surface of the first lens, the curvature radius R2 of the image side surface of the first lens, the inner diameter d0s of the object side end surface of the lens barrel, and the outer diameter D0s of the object side end surface of the lens barrel may satisfy: 0 < (d0s × D0s) / (R1 × R2) < 2.2. By controlling the curvature radii of the object side surface and the image side surface of the first lens, the deflection angle of the marginal field of view in the first lens can be adjusted to ensure that the chief ray in the incident light is transmitted along a predetermined path. At the same time, by reasonably matching the inner and outer diameters of the object side end surface of the lens barrel, the head size of the optical imaging system can be limited, thereby limiting the maximum half field angle of the optical imaging system.

[0054] In an exemplary embodiment, the length L of the lens barrel in the direction of the optical axis, the air gap T12 between the first lens and the second lens on the optical axis, the air gap T45 between the fourth lens and the fifth lens on the optical axis, and the air gap T56 between the fifth lens and the sixth lens on the optical axis may satisfy: 2.6 < L / (T12 + T45 + T56) < 3.6. By reasonably configuring the mutual relationship among the length of the lens barrel in the direction of the optical axis, the air gaps between the first lens and the second lens, the fourth lens and the fifth lens, and the fifth lens and the sixth lens on the optical axis, not only can the structure of the lens group be made more compact, but also a good fit between the image side end surface of the lens barrel and the lens group can be achieved.

[0055] In an exemplary embodiment, the effective focal length f3 of the third lens, the effective focal length f4 of the fourth lens, the inner diameter d3s of the object side surface of the third spacer element, and the outer diameter D3s of the object side surface of the third spacer element may satisfy: -1.3 < (d3s × D3s) / (f3 × f4) < 0. By reasonably configuring the mutual relationship among the effective focal length of the third lens, the effective focal length of the fourth lens, and the inner and outer diameters of the object side surface of the third spacer element, the radial dimension of the third spacer element can be constrained, which is beneficial to reducing the overall size of the optical imaging system and reducing the influence of stray light.

[0056] In an exemplary embodiment, the radius of curvature R6 of the image side surface of the third lens, the radius of curvature R7 of the object side surface of the fourth lens, the inner diameter d3m and the outer diameter D3m of the image side surface of the third spacer element may satisfy: 1.3 < (R6 / R7)×(D3m / d3m) < 2.1. By controlling the radius of curvature of the image side surface of the third lens and the radius of curvature of the object side surface of the fourth lens, the deflection angle of the marginal field of view in the fourth lens can be adjusted, ensuring that the chief ray in the incident light is transmitted along a predetermined path, effectively reducing the sensitivity of the optical imaging system. At the same time, with a reasonable inner and outer diameters of the image side surface of the third spacer element, the third spacer element can effectively block the stray light generated by the incident light in the fourth lens without affecting the path of the chief ray in the incident light.

[0057] In an exemplary embodiment, the effective focal length f4 of the fourth lens, the radius of curvature R8 of the image side surface of the fourth lens, the inner diameter d4m and the outer diameter D4m of the image side surface of the fourth spacer element may satisfy: 0.2 < |f4 / R8|×(D4m / d4m) < 1.8. By controlling the effective focal length of the fourth lens and the radius of curvature of the image side surface of the fourth lens, the deflection angle of the marginal field of view in the fourth lens can be adjusted, ensuring that the chief ray in the incident light is transmitted along a predetermined path, effectively reducing the sensitivity of the optical imaging system. At the same time, with a reasonable inner and outer diameters of the image side surface of the fourth spacer element, the fourth spacer element can effectively block the stray light generated by the incident light in the fourth lens without affecting the path of the chief ray in the incident light.

[0058] In an exemplary embodiment, the total effective focal length f of the optical imaging system, the effective focal length f5 of the fifth lens, and the outer diameter D4s of the object side surface of the fourth spacer element may satisfy: 0.5 < D4s / (f + f5) < 1.1. By reasonably configuring the relationship among the total effective focal length of the optical imaging system, the effective focal length of the fifth lens, and the outer diameter of the object side surface of the fourth spacer element, the radial dimension of the fourth spacer element can be restricted, which is beneficial to reducing the overall size of the optical imaging system.

[0059] In an exemplary embodiment, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the inner diameter d5s of the object side surface of the fifth spacer element, the outer diameter D5s of the object side surface of the fifth spacer element, the inner diameter d5m and the outer diameter D5m of the image side surface of the fifth spacer element may satisfy: 0 < (D5s + D5m - d5s - d5m) / (f5 - f6) < 1. By controlling the effective focal lengths of the fifth lens and the sixth lens, the imaging quality of the optical imaging system can be improved, and the sensitivities of the fifth lens and the sixth lens can be restricted. At the same time, by selecting reasonable inner and outer diameters of the fifth spacer element according to the sensitivities of the fifth lens and the sixth lens, the assembly stability of the optical imaging system can be improved.

[0060] In an exemplary embodiment, the air gap T34 between the third and fourth lenses on the optical axis, the center thickness CT4 of the fourth lens on the optical axis, the maximum thickness CP3 of the third spacer element, and the spacing EP34 between the third and fourth spacers along the optical axis can satisfy: 1.1 < (T34 + CT4) / (CP3 + EP34) < 2.5. Reasonably configuring the interrelationships between the air gap between the third and fourth lenses on the optical axis, the center thickness of the fourth lens on the optical axis, the maximum thickness of the third spacer element, and the spacing between the third and fourth spacers along the optical axis not only effectively restricts the positions of the third and fourth lenses, improving the structural compactness of the optical imaging system, but also helps correct off-axis aberrations and improve the overall image quality of the optical imaging system.

[0061] In an exemplary embodiment, the effective focal length f4 of the fourth lens, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the maximum thickness CP4 of the fourth spacer element, the maximum thickness CP5 of the fifth spacer element, and the spacing EP45 of the fourth and fifth spacer elements along the optical axis can satisfy: (CP4+EP45+CP5) / |f4+f5+f6|<0.3. By controlling the ratio of the maximum thickness of the fourth spacer element, the spacing of the fourth and fifth spacer elements along the optical axis, and the sum of the maximum thickness of the fifth spacer element to the sum of the effective focal lengths of the fourth to sixth lenses within a reasonable range, it is beneficial to rationally allocate the optical power of each lens and clarify the relative positions of the fourth, fifth, and sixth lenses, making the structure of the optical imaging system more compact and improving the imaging quality of the optical imaging system.

[0062] In an exemplary embodiment, the combined focal length f34 of the third and fourth lenses, the combined focal length f56 of the fifth and sixth lenses, and the inner diameter d4s of the object-side surface of the fourth spacer element and the inner diameter d5s of the object-side surface of the fifth spacer element can satisfy: 0.4 < |f56 / f34| × (d5s / d4s) < 2.5. By controlling the combined focal lengths of the third and fourth lenses and the fifth and sixth lenses, the relative positions of the third, fourth, fifth, and sixth lenses can be rationally configured, improving the imaging quality of the optical imaging system. Simultaneously, by using appropriate inner diameters of the object-side surfaces of the fourth and fifth spacers, the fourth and fifth spacers can effectively block stray light without affecting the path of the principal ray in the incident light.

[0063] In an exemplary embodiment, the total effective focal length f of the optical imaging system, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the maximum thickness CP4 of the fourth spacer element, and the maximum thickness CP5 of the fifth spacer element may satisfy: 2.1 < f / (CP2 + CP3 + CP4 + CP5) < 5.2. By controlling the ratio of the total effective focal length of the optical imaging system to the sum of the maximum thicknesses of each spacer element from the second spacer element to the fifth spacer element within a certain range, the spacing of each lens can be reasonably distributed, thereby restricting the overall optical length of the optical imaging system, reducing the sensitivity to gaps, and contributing to improving the imaging quality of the optical imaging system.

[0064] The optical imaging system according to the above embodiment of the present application may employ six lenses and at least one spacer element. By reasonably distributing the parameters of each lens and each spacer element, the structure of the optical imaging system can be made more compact, the sensitivity of the optical imaging system can be reduced, the stray light phenomenon of the optical imaging system can be improved, and the assembly stability and imaging quality of the optical imaging system can be enhanced.

[0065] In an embodiment of the present application, at least one of the surfaces of each of the first lens to the sixth lens is an aspherical surface. The characteristics of an aspherical lens are that the curvature changes continuously from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using an aspherical lens, the aberration that appears during imaging can be eliminated as much as possible, thereby improving the imaging quality. Optionally, both the object side and the image side of each of the first lens to the sixth lens are aspherical surfaces.

[0066] However, those skilled in the art should understand that without departing from the technical solutions claimed in the present application, the number of lenses and spacer elements constituting the optical imaging system can be changed to obtain the various results and advantages described in this specification.

[0067] The second aspect of the present application provides an optical imaging system that may include a lens barrel and a six - lens group and a spacer element group disposed within the lens barrel. The six - lens group may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged in sequence from the object side to the image side along the optical axis. Among them, the first lens and the sixth lens have negative optical power, the second lens and the fifth lens have positive optical power, and the signs of the optical power of the third lens and the fourth lens are opposite.

[0068] Specifically, the radius of curvature R12 of the image-side surface of the sixth lens, the central thickness CT6 of the sixth lens on the optical axis, and the inner diameter d0m and outer diameter D0m of the image-side end face of the lens barrel can satisfy: 9.3 < (R12 / CT6) × (D0m / d0m) < 13.8. Reasonably configuring the relationship between the radius of curvature of the image-side surface of the sixth lens, the central thickness of the sixth lens on the optical axis, and the inner and outer diameters of the image-side end face of the lens barrel can not only improve the manufacturability of the sixth lens but also reduce its radial dimension and the overall optical length of the optical imaging system, thereby limiting the overall size of the optical imaging system.

[0069] A third aspect of this application provides an optical imaging system that may include a lens barrel and a six-element lens group and a spacer element group disposed within the lens barrel. The six-element lens group may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical axis from the object side to the image side. The first and sixth lenses have negative optical power, the second and fifth lenses have positive optical power, and the third and fourth lenses have opposite optical power attributes. The object side and image side of the sixth lens are concave. The spacer element group may include a second spacer element disposed on the image side of the second lens and in at least partial contact with the image side of the second lens.

[0070] Specifically, the effective focal length f2 of the second lens and the effective focal length f3 of the third lens can satisfy: 1.2 < |f3| / f2 < 3.6. The effective focal length f2 of the second lens, the radius of curvature R4 of the image-side surface of the second lens, the outer diameter D2m of the image-side surface of the second spacer element, and the maximum thickness CP2 of the second spacer element can satisfy: -8.5 < (f2 / R4) × (D2m / CP2) < -6.1. With the effective focal lengths of the second and third lenses satisfying 1.2 < |f3| / f2 < 3.6, a reasonable configuration of the relationships between the effective focal length of the second lens, the radius of curvature of the image-side surface of the second lens, the outer diameter of the image-side surface of the second spacer element, and the maximum thickness of the second spacer element can adjust the deflection angle of the edge field of view in the second lens, ensuring that the principal ray in the incident light propagates along a predetermined path, effectively reducing the sensitivity of the second and third lenses, and improving the performance of the optical imaging system.

[0071] Specific embodiments of the optical imaging system applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

[0072] Example 1

[0073] The following is for reference Figure 6 An optical imaging system according to Embodiment 1 of this application is described.

[0074] like Figure 6As shown, the optical imaging system 100 includes a lens barrel P0 and a six-element lens group and a spacer element group disposed within the lens barrel P0. The six-element lens group, from the object side to the image side, includes: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6. An aperture stop STO can be disposed between the first lens E1 and the second lens E2. The spacer element group includes: a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5. The spacer elements can block excess light from entering the next lens during the imaging process, while also allowing the lens to better contact the lens barrel P0, thus enhancing the structural stability of the optical imaging system.

[0075] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0076] Table 1 shows the basic parameters of the optical imaging system of Example 1, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0077]

[0078] Table 1

[0079] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the sixth lens E6 are aspherical surfaces, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0080]

[0081] Where x is the distance vector from the vertex of the aspherical surface at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 gives the higher-order coefficients A4, A6, A8, A12 that can be used for each aspherical surface S1-S12 in Example 1. 10 A 12 A 14 and A 16.

[0082]

[0083]

[0084] Table 2

[0085] Example 2

[0086] The following is for reference Figure 7 An optical imaging system according to Embodiment 2 of this application is described.

[0087] like Figure 7 As shown, the optical imaging system 200 includes a lens barrel P0 and a six-element lens group and a spacer element group disposed within the lens barrel P0. The six-element lens group, from the object side to the image side, includes, in sequence: 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. An aperture stop STO can be disposed between the first lens E1 and the second lens E2. The spacer element group includes: a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5.

[0088] The lens structure in this embodiment is the same as that in Embodiment 1. That is, the basic parameter table of the optical imaging system in this embodiment is the same as Table 1, and the aspherical coefficient table is the same as Table 2. The difference between this embodiment and Embodiment 1 is that the structural dimensions of the lens barrel P0, the second spacer element P2, the third spacer element P3, the fourth spacer element P4, and the fifth spacer element P5 are different. For example, the inner diameter d2s of the object side of the second spacer element, the inner diameter d2m of the image side of the second spacer element, the outer diameter D2s of the object side of the second spacer element, the inner diameter D2m of the image side of the second spacer element, the inner diameter d3s of the object side of the third spacer element, the inner diameter d3m of the image side of the third spacer element, the outer diameter D3s of the object side of the third spacer element, the outer diameter D3m of the image side of the third spacer element, the inner diameter d4s of the object side of the fourth spacer element, the inner diameter d4m of the image side of the fourth spacer element, the outer diameter D4s of the object side of the fourth spacer element, the outer diameter D4m of the image side of the fourth spacer element, the inner diameter d5s of the object side of the fifth spacer element, and the fifth spacer element. The parameters such as the inner diameter d5m of the image side of the lens element, the outer diameter D5s of the object side of the fifth spacer element, the outer diameter D5m of the image side of the fifth spacer element, the inner diameter d0s of the object side end face of the lens tube, the inner diameter d0m of the image side end face of the lens tube, the outer diameter D0s of the object side end face of the lens tube, the outer diameter D0m of the image side end face of the lens tube, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the spacing EP34 between the third and fourth spacer elements along the optical axis, the maximum thickness CP4 of the fourth spacer element, the spacing EP45 between the fourth and fifth spacer elements along the optical axis, the maximum thickness CP5 of the fifth spacer element, and the length L of the lens tube in the direction of the optical axis are different.

[0089] Example 3

[0090] The following is for reference Figure 8 An optical imaging system according to Embodiment 3 of this application is described.

[0091] like Figure 8 As shown, the optical imaging system 300 includes a lens barrel P0 and a six-element lens group and a spacer element group disposed within the lens barrel P0. The six-element lens group, from the object side to the image side, includes, in sequence: 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. An aperture stop STO can be disposed between the first lens E1 and the second lens E2. The spacer element group includes, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5.

[0092] The lens structure in this embodiment is the same as that in Embodiment 1. That is, the basic parameter table of the optical imaging system in this embodiment is the same as Table 1, and the aspherical coefficient table is the same as Table 2. The difference between this embodiment and Embodiment 1 is that the structural dimensions of the lens barrel P0, the second spacer element P2, the third spacer element P3, the fourth spacer element P4, and the fifth spacer element P5 are different. For example, the inner diameter d2s of the object side of the second spacer element, the inner diameter d2m of the image side of the second spacer element, the outer diameter D2s of the object side of the second spacer element, the inner diameter D2m of the image side of the second spacer element, the inner diameter d3s of the object side of the third spacer element, the inner diameter d3m of the image side of the third spacer element, the outer diameter D3s of the object side of the third spacer element, the outer diameter D3m of the image side of the third spacer element, the inner diameter d4s of the object side of the fourth spacer element, the inner diameter d4m of the image side of the fourth spacer element, the outer diameter D4s of the object side of the fourth spacer element, the outer diameter D4m of the image side of the fourth spacer element, the inner diameter d5s of the object side of the fifth spacer element, and the fifth spacer element. The parameters such as the inner diameter d5m of the image side of the lens element, the outer diameter D5s of the object side of the fifth spacer element, the outer diameter D5m of the image side of the fifth spacer element, the inner diameter d0s of the object side end face of the lens tube, the inner diameter d0m of the image side end face of the lens tube, the outer diameter D0s of the object side end face of the lens tube, the outer diameter D0m of the image side end face of the lens tube, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the spacing EP34 between the third and fourth spacer elements along the optical axis, the maximum thickness CP4 of the fourth spacer element, the spacing EP45 between the fourth and fifth spacer elements along the optical axis, the maximum thickness CP5 of the fifth spacer element, and the length L of the lens tube in the direction of the optical axis are different.

[0093] Figure 9A The on-axis chromatic aberration curves of the optical imaging systems of Examples 1, 2 and 3 are shown, which represent the deflection of the focal point after light of different wavelengths passes through the optical imaging system. Figure 9B Astigmatism curves of the optical imaging systems of Examples 1, 2 and 3 are shown, representing the meridional and sagittal image plane curvatures corresponding to different image heights. Figure 9C Distortion curves for the optical imaging systems of Examples 1, 2, and 3 are shown, representing the distortion magnitude values ​​corresponding to different image heights. According to... Figures 9A to 9C It can be seen that the optical imaging systems given in Examples 1, 2 and 3 can achieve good imaging quality.

[0094] Example 4

[0095] The following is for reference Figure 10 The optical imaging system according to Embodiment 4 of this application is described.

[0096] like Figure 10As shown, the optical imaging system 400 includes a lens barrel P0 and a six-element lens group and a spacer element group disposed within the lens barrel P0. The six-element lens group, from the object side to the image side, includes: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6. An aperture stop STO can be disposed between the first lens E1 and the second lens E2. The spacer element group includes: a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5. The spacer elements can block excess light from entering the next lens during the imaging process, while also allowing the lens to better contact the lens barrel P0, thus enhancing the structural stability of the optical imaging system.

[0097] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being concave and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0098] Table 3 shows the basic parameters of the optical imaging system of Example 4, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0099]

[0100] Table 3

[0101] In this embodiment, the object-side surface and image-side surface of any one of the lenses, from the first lens E1 to the sixth lens E6, are aspherical. Table 4 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for the aspherical surfaces S1-S12 in Embodiment 4. 10 A 12 A 14 and A 16 .

[0102] Face number A4 A6 A8 A10 A12 A14 A16 S1 5.3530E-03 5.5944E-03 -5.1516E-02 8.5538E-02 -6.6786E-02 2.5677E-02 -3.9256E-03 S2 6.7215E-02 -9.6751E-02 9.3328E-01 -3.6338E+00 7.6131E+00 -7.8087E+00 3.2575E+00 S3 -3.2741E-02 5.2083E-02 -4.0829E-01 1.3047E+00 -2.3728E+00 2.1906E+00 -8.5286E-01 S4 -2.0206E-01 6.5647E-04 4.3282E-01 -8.2242E-01 8.5986E-01 -5.1282E-01 1.2783E-01 S5 -2.6645E-01 -5.4066E-02 -2.1073E-01 1.4248E+00 -2.3947E+00 1.7886E+00 -5.0080E-01 S6 -9.1744E-02 1.0603E+00 -3.1389E+00 4.5815E+00 -3.6242E+00 1.5133E+00 -2.6515E-01 S7 -1.7928E-01 1.6012E+00 -4.2264E+00 5.5655E+00 -3.9303E+00 1.4426E+00 -2.1762E-01 S8 -1.8054E-01 -7.8645E-02 1.1473E-02 1.8240E-01 -2.1140E-01 1.2065E-01 -2.5802E-02 S9 1.3650E-01 -2.7011E-01 2.7449E-01 -2.3475E-01 1.5100E-01 -5.4015E-02 7.8118E-03 S10 -1.3580E-01 4.9439E-01 -7.3243E-01 5.7346E-01 -2.6691E-01 7.4026E-02 -9.1947E-03 S11 -3.8551E-02 -1.9620E-01 2.7493E-01 -1.7859E-01 7.3786E-02 -1.8022E-02 1.9325E-03 S12 -1.6484E-01 3.0050E-02 3.1251E-02 -2.8981E-02 1.0768E-02 -1.9716E-03 1.2498E-04

[0103] Table 4

[0104] Example 5

[0105] The following is for reference Figure 11 An optical imaging system according to Embodiment 5 of this application is described.

[0106] like Figure 11 As shown, the optical imaging system 500 includes a lens barrel P0 and a six-element lens group and a spacer element group disposed within the lens barrel P0. The six-element lens group, from the object side to the image side, includes, in sequence: 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. An aperture stop STO can be disposed between the first lens E1 and the second lens E2. The spacer element group includes, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5.

[0107] The lens structure in this embodiment is the same as that in Embodiment 4. That is, the basic parameter table of the optical imaging system in this embodiment is the same as that in Table 3, and the aspherical coefficient table is the same as that in Table 4. The difference between this embodiment and Embodiment 4 is that the structural dimensions of the lens barrel P0, the second spacer element P2, the third spacer element P3, the fourth spacer element P4, and the fifth spacer element P5 are different. For example, the inner diameter d2s of the object side of the second spacer element, the inner diameter d2m of the image side of the second spacer element, the outer diameter D2s of the object side of the second spacer element, the inner diameter D2m of the image side of the second spacer element, the inner diameter d3s of the object side of the third spacer element, the inner diameter d3m of the image side of the third spacer element, the outer diameter D3s of the object side of the third spacer element, the outer diameter D3m of the image side of the third spacer element, the inner diameter d4s of the object side of the fourth spacer element, the inner diameter d4m of the image side of the fourth spacer element, the outer diameter D4s of the object side of the fourth spacer element, the outer diameter D4m of the image side of the fourth spacer element, the inner diameter d5s of the object side of the fifth spacer element, and the fifth spacer element. The parameters such as the inner diameter d5m of the image side of the lens element, the outer diameter D5s of the object side of the fifth spacer element, the outer diameter D5m of the image side of the fifth spacer element, the inner diameter d0s of the object side end face of the lens tube, the inner diameter d0m of the image side end face of the lens tube, the outer diameter D0s of the object side end face of the lens tube, the outer diameter D0m of the image side end face of the lens tube, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the spacing EP34 between the third and fourth spacer elements along the optical axis, the maximum thickness CP4 of the fourth spacer element, the spacing EP45 between the fourth and fifth spacer elements along the optical axis, the maximum thickness CP5 of the fifth spacer element, and the length L of the lens tube in the direction of the optical axis are different.

[0108] Example 6

[0109] The following is for reference Figure 12 An optical imaging system according to Embodiment 6 of this application is described.

[0110] like Figure 12As shown, the optical imaging system 600 includes a lens barrel P0 and a six-element lens group and a spacer element group disposed within the lens barrel P0. The six-element lens group, from the object side to the image side, includes: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6. An aperture stop STO can be disposed between the first lens E1 and the second lens E2. The spacer element group includes: a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5.

[0111] The lens structure in this embodiment is the same as that in Embodiment 4. That is, the basic parameter table of the optical imaging system in this embodiment is the same as that in Table 3, and the aspherical coefficient table is the same as that in Table 4. The difference between this embodiment and Embodiment 4 is that the structural dimensions of the lens barrel P0, the second spacer element P2, the third spacer element P3, the fourth spacer element P4, and the fifth spacer element P5 are different. For example, the inner diameter d2s of the object side of the second spacer element, the inner diameter d2m of the image side of the second spacer element, the outer diameter D2s of the object side of the second spacer element, the inner diameter D2m of the image side of the second spacer element, the inner diameter d3s of the object side of the third spacer element, the inner diameter d3m of the image side of the third spacer element, the outer diameter D3s of the object side of the third spacer element, the outer diameter D3m of the image side of the third spacer element, the inner diameter d4s of the object side of the fourth spacer element, the inner diameter d4m of the image side of the fourth spacer element, the outer diameter D4s of the object side of the fourth spacer element, the outer diameter D4m of the image side of the fourth spacer element, the inner diameter d5s of the object side of the fifth spacer element, and the fifth spacer element. The parameters such as the inner diameter d5m of the image side of the lens element, the outer diameter D5s of the object side of the fifth spacer element, the outer diameter D5m of the image side of the fifth spacer element, the inner diameter d0s of the object side end face of the lens tube, the inner diameter d0m of the image side end face of the lens tube, the outer diameter D0s of the object side end face of the lens tube, the outer diameter D0m of the image side end face of the lens tube, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the spacing EP34 between the third and fourth spacer elements along the optical axis, the maximum thickness CP4 of the fourth spacer element, the spacing EP45 between the fourth and fifth spacer elements along the optical axis, the maximum thickness CP5 of the fifth spacer element, and the length L of the lens tube in the direction of the optical axis are different.

[0112] Figure 13A The on-axis chromatic aberration curves of the optical imaging systems of Examples 4, 5 and 6 are shown, which represent the deflection of the focal point after light of different wavelengths passes through the optical imaging system. Figure 13B Astigmatism curves of the optical imaging systems of Examples 4, 5, and 6 are shown, representing the meridional and sagittal image plane curvatures corresponding to different image heights. Figure 13C Distortion curves for the optical imaging systems of Examples 4, 5, and 6 are shown, representing the distortion magnitude values ​​corresponding to different image heights. According to... Figures 13A to 13CIt can be seen that the optical imaging systems given in Examples 4, 5 and 6 can achieve good imaging quality.

[0113] Example 7

[0114] The following is for reference Figure 14 An optical imaging system according to Embodiment 7 of this application is described.

[0115] like Figure 14 As shown, the optical imaging system 700 includes a lens barrel P0 and a six-element lens group and a spacer element group disposed within the lens barrel P0. The six-element lens group, from the object side to the image side, includes: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6. An aperture stop STO can be disposed between the first lens E1 and the second lens E2. The spacer element group includes: a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5. The spacer elements can block excess light from entering the next lens during the imaging process, while also allowing the lens to better contact the lens barrel P0, thus enhancing the structural stability of the optical imaging system.

[0116] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0117] Table 5 shows the basic parameters of the optical imaging system of Example 7, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0118]

[0119]

[0120] Table 5

[0121] In this embodiment, the object-side surface and image-side surface of any one of the lenses, from the first lens E1 to the sixth lens E6, are aspherical. Table 6 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for the aspherical surfaces S1-S12 in Embodiment 7. 10 A 12 A14 and A 16 .

[0122] Face number A4 A6 A8 A10 A12 A14 A16 S1 7.5887E-03 -1.7130E-02 7.4595E-03 3.8535E-03 -5.3059E-03 2.0347E-03 -2.7219E-04 S2 7.8517E-02 -1.2575E-01 7.7041E-01 -2.3239E+00 4.0801E+00 -3.6416E+00 1.3468E+00 S3 -2.4704E-02 2.7609E-02 -3.7068E-01 1.0432E+00 -1.7148E+00 1.4439E+00 -5.2895E-01 S4 -8.0427E-02 -1.0804E-01 -1.9391E-01 1.1513E+00 -1.6314E+00 9.8870E-01 -2.2806E-01 S5 -2.9455E-01 7.9995E-01 -3.0975E+00 6.0917E+00 -6.3764E+00 3.4653E+00 -7.7278E-01 S6 -1.9388E-01 1.1210E+00 -3.1683E+00 4.8531E+00 -4.1726E+00 1.9367E+00 -3.7969E-01 S7 -7.7450E-02 9.9294E-02 6.1611E-02 -6.0148E-01 8.8645E-01 -4.9832E-01 9.9316E-02 S8 6.1741E-02 -7.8135E-01 1.2150E+00 -8.6289E-01 2.7553E-01 -1.0065E-02 -6.4964E-03 S9 1.6078E-01 -6.5052E-01 4.5306E-01 5.2481E-01 -9.0612E-01 4.7171E-01 -8.7235E-02 S10 -2.9990E-02 4.0891E-02 -3.0933E-01 5.8714E-01 -4.4380E-01 1.4261E-01 -1.4748E-02 S11 -1.7737E-01 -1.5765E-03 2.1500E-01 -2.0450E-01 7.6347E-02 -6.6406E-03 -1.2598E-03 S12 -2.9377E-01 2.1673E-01 -1.2184E-01 4.9745E-02 -1.5595E-02 3.4638E-03 -4.0341E-04

[0123] Table 6

[0124] Example 8

[0125] The following is for reference Figure 15 An optical imaging system according to Embodiment 8 of this application is described.

[0126] like Figure 15 As shown, the optical imaging system 800 includes a lens barrel P0 and a six-element lens group and a spacer element group disposed within the lens barrel P0. The six-element lens group, from the object side to the image side, includes: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6. An aperture stop STO can be disposed between the first lens E1 and the second lens E2. The spacer element group includes: a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5.

[0127] The lens structure in this embodiment is the same as that in Embodiment 7. That is, the basic parameter table of the optical imaging system in this embodiment is the same as that in Table 5, and the aspherical coefficient table is the same as that in Table 6. The difference between this embodiment and Embodiment 7 is that the structural dimensions of the lens barrel P0, the second spacer element P2, the third spacer element P3, the fourth spacer element P4, and the fifth spacer element P5 are different. For example, the inner diameter d2s of the object side of the second spacer element, the inner diameter d2m of the image side of the second spacer element, the outer diameter D2s of the object side of the second spacer element, the inner diameter D2m of the image side of the second spacer element, the inner diameter d3s of the object side of the third spacer element, the inner diameter d3m of the image side of the third spacer element, the outer diameter D3s of the object side of the third spacer element, the outer diameter D3m of the image side of the third spacer element, the inner diameter d4s of the object side of the fourth spacer element, the inner diameter d4m of the image side of the fourth spacer element, the outer diameter D4s of the object side of the fourth spacer element, the outer diameter D4m of the image side of the fourth spacer element, the inner diameter d5s of the object side of the fifth spacer element, and the fifth spacer element. The parameters such as the inner diameter d5m of the image side of the lens element, the outer diameter D5s of the object side of the fifth spacer element, the outer diameter D5m of the image side of the fifth spacer element, the inner diameter d0s of the object side end face of the lens tube, the inner diameter d0m of the image side end face of the lens tube, the outer diameter D0s of the object side end face of the lens tube, the outer diameter D0m of the image side end face of the lens tube, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the spacing EP34 between the third and fourth spacer elements along the optical axis, the maximum thickness CP4 of the fourth spacer element, the spacing EP45 between the fourth and fifth spacer elements along the optical axis, the maximum thickness CP5 of the fifth spacer element, and the length L of the lens tube in the direction of the optical axis are different.

[0128] Example 9

[0129] The following is for reference Figure 16 An optical imaging system according to Embodiment 9 of this application is described.

[0130] like Figure 16 As shown, the optical imaging system 900 includes a lens barrel P0 and a six-element lens group and a spacer element group disposed within the lens barrel P0. The six-element lens group, from the object side to the image side, includes: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6. An aperture stop STO can be disposed between the first lens E1 and the second lens E2. The spacer element group includes: a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5.

[0131] The lens structure in this embodiment is the same as that in Embodiment 7. That is, the basic parameter table of the optical imaging system in this embodiment is the same as that in Table 5, and the aspherical coefficient table is the same as that in Table 6. The difference between this embodiment and Embodiment 7 is that the structural dimensions of the lens barrel P0, the second spacer element P2, the third spacer element P3, the fourth spacer element P4, and the fifth spacer element P5 are different. For example, the inner diameter d2s of the object side of the second spacer element, the inner diameter d2m of the image side of the second spacer element, the outer diameter D2s of the object side of the second spacer element, the inner diameter D2m of the image side of the second spacer element, the inner diameter d3s of the object side of the third spacer element, the inner diameter d3m of the image side of the third spacer element, the outer diameter D3s of the object side of the third spacer element, the outer diameter D3m of the image side of the third spacer element, the inner diameter d4s of the object side of the fourth spacer element, the inner diameter d4m of the image side of the fourth spacer element, the outer diameter D4s of the object side of the fourth spacer element, the outer diameter D4m of the image side of the fourth spacer element, the inner diameter d5s of the object side of the fifth spacer element, and the fifth spacer element. The parameters such as the inner diameter d5m of the image side of the lens element, the outer diameter D5s of the object side of the fifth spacer element, the outer diameter D5m of the image side of the fifth spacer element, the inner diameter d0s of the object side end face of the lens tube, the inner diameter d0m of the image side end face of the lens tube, the outer diameter D0s of the object side end face of the lens tube, the outer diameter D0m of the image side end face of the lens tube, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the spacing EP34 between the third and fourth spacer elements along the optical axis, the maximum thickness CP4 of the fourth spacer element, the spacing EP45 between the fourth and fifth spacer elements along the optical axis, the maximum thickness CP5 of the fifth spacer element, and the length L of the lens tube in the direction of the optical axis are different.

[0132] Figure 17A The on-axis chromatic aberration curves of the optical imaging systems of Examples 7, 8 and 9 are shown, which represent the deflection of the focal point after light of different wavelengths passes through the optical imaging system. Figure 17B Astigmatism curves of the optical imaging systems of Examples 7, 8, and 9 are shown, representing the meridional and sagittal image plane curvatures corresponding to different image heights. Figure 17C Distortion curves for the optical imaging systems of Examples 7, 8, and 9 are shown, representing the magnitude of distortion at different image heights. According to... Figures 17A to 17C It can be seen that the optical imaging systems given in Examples 7, 8 and 9 can achieve good imaging quality.

[0133] Table 7 shows the optical imaging systems of each embodiment in Examples 1 to 9 and the focal length values ​​of each lens, wherein the unit of focal length is millimeters (mm).

[0134] Focal length / Example 1 2 3 4 5 6 7 8 9 f 2.08 2.08 2.08 2.08 2.08 2.08 2.08 2.08 2.08 f1 -3.21 -3.21 -3.21 -3.13 -3.13 -3.13 -3.09 -3.09 -3.09 f2 2.50 2.50 2.50 2.49 2.49 2.49 2.52 2.52 2.52 f3 -3.18 -3.18 -3.18 8.75 8.75 8.75 -3.45 -3.45 -3.45 f4 2.55 2.55 2.55 -3.74 -3.74 -3.74 2.24 2.24 2.24 f5 2.40 2.40 2.40 1.54 1.54 1.54 3.14 3.14 3.14 f6 -1.84 -1.84 -1.84 -1.62 -1.62 -1.62 -1.87 -1.87 -1.87 f34 14.05 14.05 14.05 -6.80 -6.80 -6.80 6.09 6.09 6.09 f56 29.24 29.24 29.24 2.76 2.76 2.76 -9.57 -9.57 -9.57

[0135] Table 7

[0136] Table 8 lists some basic parameters of the lens barrel and spacer elements in each embodiment from Examples 1 to 9, such as d2s, d2m, D2s, D2m, d3s, d3m, D3s, D3m, d4s, d4m, D4s, D4m, d5s, d5m, D5s, D5m, d0s, d0m, D0s, D0m, CP2, CP3, EP34, CP4, EP45, CP5, and L, etc. Some of the basic parameters listed in Table 8 are based on... Figure 1 The measurements were obtained using the annotation method shown, and the units of the basic parameters listed in Table 8 are all millimeters (mm).

[0137]

[0138]

[0139] Table 8

[0140] Table 9 shows the values ​​of the conditional expressions for each of the embodiments in Examples 1 to 9.

[0141] Conditional / Example 1 2 3 4 5 6 7 8 9 |f3| / f2 1.27 1.27 1.27 3.51 3.51 3.51 1.37 1.37 1.37 (R4 / R3)×(D2s / d2s) -2.14 -2.78 -2.83 -2.40 -2.27 -2.27 -2.47 -2.36 -2.21 (R12 / CT6)×(D0m / d0m) 13.65 13.71 13.71 9.49 9.35 9.53 12.80 12.89 12.84 (f2 / R4)×(D2m / CP2) -6.20 -7.95 -7.93 -8.00 -7.56 -7.56 -8.40 -7.79 -7.54 (d2m×D2m) / |f2×f3| 0.90 1.16 1.14 0.37 0.35 0.35 1.01 0.94 0.91 (d0s×D0s) / (R1×R2) 2.16 1.59 1.59 0.84 0.92 0.84 0.66 0.65 0.68 L / (T12+T45+T56) 2.76 2.65 2.65 3.51 3.51 3.51 2.90 2.90 2.90 (d3s×D3s) / (f3×f4) -0.95 -1.20 -1.20 -0.28 -0.27 -0.27 -1.26 -1.14 -1.20 (R6 / R7)×(D3m / d3m) 1.60 2.01 2.01 1.43 1.36 1.36 1.85 1.67 1.76 |f4 / R8|×(D4m / d4m) 0.24 0.30 0.30 1.73 1.65 1.65 0.39 0.35 0.29 D4s / (f+f5) 0.75 0.95 0.95 1.02 0.97 0.97 0.82 0.75 0.61 (D5s+D5m-d5s-d5m) / (f5-f6) 0.39 0.47 0.94 0.88 0.75 0.77 0.73 0.57 0.65 (T34+CT4) / (CP3+EP34) 2.41 2.41 2.41 1.13 1.13 1.13 1.97 1.97 2.45 (CP4+EP45+CP5) / |f4+f5+f6| 0.27 0.24 0.24 0.25 0.25 0.20 0.11 0.11 0.14 |f56 / f34|×(d5s / d4s) 2.45 2.39 2.39 0.47 0.47 0.45 1.68 1.68 1.70 f / (CP2+CP3+CP4+CP5) 2.12 2.80 2.80 2.67 2.67 2.67 5.17 5.17 5.17

[0142] Table 9

[0143] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An optical imaging system, characterized by, Comprise: a six-lens group comprising, in order from the object side to the image side along the optical axis: a first lens with negative refractive power, whose object side surface is convex and whose image side surface is concave; a second lens with positive refractive power, whose object side surface is convex and whose image side surface is convex; a third lens; a fourth lens; a fifth lens with positive refractive power, whose image side surface is convex; a sixth lens with negative refractive power, whose object side surface is concave and whose image side surface is concave; a spacer element group comprising a second spacer element disposed on and in contact with the image side surface of the second lens and a fourth spacer element disposed on and in contact with the image side surface of the fourth lens; and a lens barrel in which the six-lens group and the spacer element group are disposed; wherein the number of lenses with refractive power in the optical imaging system is six; the third lens and the fourth lens have opposite positive and negative refractive powers; the effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy: 1.27≤|f3| / f2≤3.51, the curvature radius R3 of the object side surface of the second lens, the curvature radius R4 of the image side surface of the second lens, the inner diameter d2s of the object side surface of the second spacer element, and the outer diameter D2s of the object side surface of the second spacer element satisfy: -2.83≤(R4 / R3)×(D2s / d2s)≤-2.14; the effective focal length f4 of the fourth lens, the curvature radius R8 of the image side surface of the fourth lens, the inner diameter d4m of the image side surface of the fourth spacer element, and the outer diameter D4m of the image side surface of the fourth spacer element satisfy: 0.2<|f4 / R8|×(D4m / d4m)≤1.

73.

2. The optical imaging system of claim 1, wherein, the curvature radius R12 of the image side surface of the sixth lens, the central thickness CT6 of the sixth lens on the optical axis, the inner diameter d0m of the image side end surface of the lens barrel, and the outer diameter D0m of the image side end surface of the lens barrel satisfy: 9.35≤(R12 / CT6)×(D0m / d0m)≤13.

71.

3. The optical imaging system of claim 1, wherein, the effective focal length f2 of the second lens, the curvature radius R4 of the image side surface of the second lens, the outer diameter D2m of the image side surface of the second spacer element, and the maximum thickness CP2 of the second spacer element satisfy: -8.40≤(f2 / R4)×(D2m / CP2)≤-6.

20.

4. The optical imaging system of claim 1, wherein, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the inner diameter d2m of the image side surface of the second spacer element, and the outer diameter D2m of the image side surface of the second spacer element satisfy: 0.35≤(d2m×D2m) / |f2×f3|<1.

2.

5. The optical imaging system of claim 1, wherein, the curvature radius R1 of the object side surface of the first lens, the curvature radius R2 of the image side surface of the first lens, the inner diameter d0s of the object side end surface of the lens barrel, and the outer diameter D0s of the object side end surface of the lens barrel satisfy: 0.65≤(d0s×D0s) / (R1×R2)<2.

2.

6. The optical imaging system of claim 1, wherein, The length L of the lens barrel in the direction of the optical axis, the air interval T12 of the first lens and the second lens on the optical axis, the air interval T45 of the fourth lens and the fifth lens on the optical axis, and the air interval T56 of the fifth lens and the sixth lens on the optical axis satisfy: 2.65 ≤ L / (T12+T45+T56) ≤ 3.

51.

7. The optical imaging system according to any one of claims 1 to 6, characterized in that, The spacer element group further includes a third spacer element disposed on and in contact with the image side surface of the third lens, wherein the effective focal length f3 of the third lens, the effective focal length f4 of the fourth lens, the inner diameter d3s of the object side surface of the third spacer element, and the outer diameter D3s of the object side surface of the third spacer element satisfy: -1.3 < (d3s×D3s) / (f3×f4) ≤ -0.

27.

8. The optical imaging system according to any one of claims 1 to 6, characterized in that, The spacer element group further includes a third spacer element disposed on and in contact with the image side surface of the third lens, wherein the radius of curvature R6 of the image side surface of the third lens, the radius of curvature R7 of the object side surface of the fourth lens, the inner diameter d3m of the image side surface of the third spacer element, and the outer diameter D3m of the image side surface of the third spacer element satisfy: 1.36 ≤ (R6 / R7)×(D3m / d3m) ≤ 2.

01.

9. The optical imaging system according to any one of claims 1 to 6, characterized in that, The total effective focal length f of the optical imaging system, the effective focal length f5 of the fifth lens, and the outer diameter D4s of the object side surface of the fourth spacer element satisfy: 0.61 ≤ D4s / (f+f5) ≤ 1.

02.

10. The optical imaging system of any one of claims 1 to 6, wherein, The spacer element group further includes a fifth spacer element disposed on and in contact with the image side surface of the fifth lens, wherein the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the inner diameter d5s of the object side surface of the fifth spacer element, the outer diameter D5s of the object side surface of the fifth spacer element, the inner diameter d5m of the image side surface of the fifth spacer element, and the outer diameter D5m of the image side surface of the fifth spacer element satisfy: 0.39 ≤ (D5s+D5m-d5s-d5m) / (f5-f6) ≤ 0.

94.

11. The optical imaging system of any one of claims 1 to 6, wherein, The spacer element group further includes a third spacer element disposed on and in contact with the image side surface of the third lens, wherein the air interval T34 of the third lens and the fourth lens on the optical axis, the central thickness CT4 of the fourth lens on the optical axis, the maximum thickness CP3 of the third spacer element, and the interval EP34 of the third spacer element and the fourth spacer element along the optical axis satisfy: 1.1 < (T34+CT4) / (CP3+EP34) ≤ 2.

45.

12. The optical imaging system of any one of claims 1 to 6, wherein, The spacer element group further includes a fifth spacer element disposed on and in contact with the image side surface of the fifth lens, The effective focal length f4 of the fourth lens, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the maximum thickness CP4 of the fourth spacer element, the maximum thickness CP5 of the fifth spacer element and the interval EP45 of the fourth spacer element and the fifth spacer element along the optical axis satisfy: 0.11≤(CP4+EP45+CP5) / |f4+f5+f6|<0.

3.

13. The optical imaging system of any one of claims 1 to 6, wherein, The spacer element group further comprises a fifth spacer element disposed on and in contact with the image side surface of the fifth lens, The combined focal length f34 of the third lens and the fourth lens, the combined focal length f56 of the fifth lens and the sixth lens, the inner diameter d4s of the object side surface of the fourth spacer element and the inner diameter d5s of the object side surface of the fifth spacer element satisfy: 0.45≤|f56 / f34|×(d5s / d4s)≤2.

45.

14. The optical imaging system of any one of claims 1 to 6, wherein, The spacer element group further comprises a third spacer element disposed on and in contact with the image side surface of the third lens and a fifth spacer element disposed on and in contact with the image side surface of the fifth lens, The total effective focal length f of the optical imaging system, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the maximum thickness CP4 of the fourth spacer element and the maximum thickness CP5 of the fifth spacer element satisfy: 2.1 The total effective focal length f of the optical imaging system, the maximum thickness CP2 of the second spacer element, the maximum thickness CP3 of the third spacer element, the maximum thickness CP4 of the fourth spacer element and the maximum thickness CP5 of the fifth spacer element satisfy: 2.1

Images