Optical imaging system

Abstract

This application discloses an optical imaging system, comprising: an imaging lens group consisting of 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; wherein the first lens has positive optical power, the second lens has negative optical power, the third and fourth lenses have different signs of optical power, the fifth lens has positive optical power, the sixth lens has negative optical power, both the object side and the image side of the sixth lens have inflection points, and the refractive indices of the second and fourth lenses are both greater than 1.6; a plurality of spacer elements including a second spacer element, a third spacer element, and a fourth spacer element; the radius of curvature R8 of the image side of the fourth lens, the spacing EP23 between the image side and the object side of the second spacer element along the optical axis, and the spacing EP34 between the image side and the object side of the third spacer element along the optical axis satisfy: 11 <R8 / (EP23+EP34)<55。

Description

[0001] Divisional application statement

[0002] This application is a divisional application of Chinese invention patent application filed on September 15, 2022, entitled "Optical Imaging System" and with application number 202211123850.1. Technical Field

[0003] This application relates to the field of optical components, and more specifically, to an optical imaging system. Background Technology

[0004] In recent years, with the widespread use of mobile phones in daily life, people have not only placed higher demands on the image quality of mobile phone lenses, but also paid more attention to the appearance and overall size of the lenses. On the one hand, they require lenses with large apertures and high pixel counts to achieve clear imaging in low-light conditions; on the other hand, customers pursue aesthetically pleasing and miniaturized lenses. For lenses with generally extreme barrel dimensions, such as 6P ultra-thin lenses with large image sensors, the range of different barrel settings is quite large, resulting in significant differences that can easily affect the performance of the imaging system. Furthermore, the large differences in size lead to poor assembly stability, which in turn affects the overall quality of the lens.

[0005] Therefore, how to ensure good image quality and structural stability of the lens while meeting the customer's requirements for its appearance and overall size is one of the key research topics for designers. Summary of the Invention

[0006] This application provides an optical imaging system comprising: an imaging lens group consisting of 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; wherein the first lens has positive optical power, the second lens has negative optical power, the third and fourth lenses have different signs of optical power, the fifth and sixth lenses have different signs of optical power, the sixth lens has inflection points on both its object-side and image-side surfaces, and the refractive indices of the second and fourth lenses are both greater than 1.6; and multiple spacer elements. The lens includes a first spacer element placed between the first lens and the second lens and in contact with the image side of the first lens, and a fifth spacer element placed between the fifth lens and the sixth lens and in contact with the image side of the fifth lens; and a lens barrel for accommodating the imaging lens group and the multiple spacer elements; the effective focal length f1 of the first lens, the effective focal length f6 of the sixth lens, the spacing EP01 of the front end face of the lens barrel near the object side and the object side side of the first spacer element along the optical axis direction and the maximum thickness CP5 of the fifth spacer element along the optical axis direction satisfy: 0.5 < (f1 + f6) / (EP01 + CP5) < 3.

[0007] In one embodiment, the plurality of spacer elements further includes a second spacer element disposed between the second lens and the third lens and in contact with the image side surface of the second lens, a third spacer element disposed between the third lens and the fourth lens and in contact with the image side surface of the third lens, and a fourth spacer element disposed between the fourth lens and the fifth lens and in contact with the image side surface of the fourth lens. Wherein, the optical imaging system satisfies: 0.5 < Dis / f < 2.0, where Dis is the outer diameter of the object side surface of the spacer element on the image side surface of the lens in the imaging lens group with an Abbe number greater than 50, and f is the effective focal length of the optical imaging system; when i = 1, D1s represents the outer diameter of the object side surface of the first spacer element; when i = 2, D2s represents the outer diameter of the object side surface of the second spacer element; when i = 3, D3s represents the outer diameter of the object side surface of the third spacer element; when i = 4, D4s represents the outer diameter of the object side surface of the fourth spacer element; and when i = 5, D5s represents the outer diameter of the object side surface of the fifth spacer element.

[0008] In one embodiment, the plurality of spacer elements further includes a second spacer element disposed between the second lens and the third lens and in contact with the image side surface of the second lens, a third spacer element disposed between the third lens and the fourth lens and in contact with the image side surface of the third lens, and a fourth spacer element disposed between the fourth lens and the fifth lens and in contact with the image side surface of the fourth lens. Wherein, the optical imaging system satisfies: 1 < Djm / EPD < 4, where Djm is the outer diameter of the image side surface of the spacer element on the image side surface of the lens with positive optical power in the imaging lens group, and EPD is the entrance pupil diameter of the optical imaging system; when j = 1, D1m represents the outer diameter of the image side surface of the first spacer element; when j = 2, D2m represents the outer diameter of the image side surface of the second spacer element; when j = 3, D3m represents the outer diameter of the image side surface of the third spacer element; when j = 4, D4m represents the outer diameter of the image side surface of the fourth spacer element; and when j = 5, D5m represents the outer diameter of the image side surface of the fifth spacer element.

[0009] In one embodiment, the on-axis distance TD from the object side surface of the first lens to the image side surface of the sixth lens, the effective focal length f of the optical imaging system, the distance EP01 between the front end surface of the lens barrel near the object side and the object side surface of the first spacer element along the optical axis, and the inner diameter d0s of the front end surface of the lens barrel near the object side satisfy: 3 < (TD × f) / (EP01 × d0s) < 8.

[0010] In one embodiment, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the inner diameter d1s of the object side surface of the first spacer element, and the inner diameter d1m of the image side surface of the first spacer element satisfy: 5 < |f1 × f2| / (d1s × d1m) < 12.

[0011] In one embodiment, at least two of the first to fourth lenses are meniscus lenses in the paraxial region.

[0012] In one embodiment, the radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: R2>R1.

[0013] In one embodiment, the plurality of spacers further includes a second spacer element disposed between the second lens and the third lens and in contact with the image side of the second lens, wherein 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 spacing EP12 between the image side of the first spacer element and the object side of the second spacer element along the optical axis, and the maximum thickness CP2 of the second spacer element along the optical axis satisfy: 30 < (R3 + R4) / (EP12 + CP2) < 77.

[0014] In one embodiment, the plurality of spacers further includes a second spacer element disposed between the second lens and the third lens and in contact with the image-side surface of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side surface of the third lens, wherein the radius of curvature R5 of the object-side surface of the third lens, the radius of curvature R6 of the image-side surface of the third lens, the inner diameter d2s of the object-side surface of the second spacer element and the inner diameter d3s of the object-side surface of the third spacer element satisfy: 0 < |R6 / R5| × (d3s / d2s) < 6.

[0015] In one embodiment, the plurality of spacers further includes a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side surface of the third lens, wherein the effective focal length f4 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: 2<|f4| / (d3m+D3m)<25.

[0016] In one embodiment, the plurality of spacers further includes a fourth spacer element disposed between the fourth lens and the fifth lens and in contact with the image-side surface of the fourth lens, wherein the effective focal length f5 of the fifth lens, the maximum thickness CP4 of the fourth spacer element along the optical axis, and the spacing EP45 between the image-side surface of the fourth spacer element and the object-side surface of the fifth spacer element along the optical axis satisfy: 3 <f5 / (CP4+EP45)<8。

[0017] In one embodiment, the plurality of spacers further includes a second spacer element disposed between the second lens and the third lens and in contact with the image-side surface of the second lens, a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side surface of the third lens, and a fourth spacer element disposed between the fourth lens and the fifth lens and in contact with the image-side surface of the fourth lens, wherein the radius of curvature R8 of the image-side surface of the fourth lens, the spacing EP23 between the image-side surface of the second spacer element and the object-side surface of the third spacer element along the optical axis, and the spacing EP34 between the image-side surface of the third spacer element and the object-side surface of the fourth spacer element along the optical axis satisfy: 11 <R8 / (EP23+EP34)<55。

[0018] In one embodiment, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, and the maximum thickness CP5 of the fifth spacer element along the optical axis satisfy: 1 ​​< |f5+f6| / CP5 < 16.

[0019] In one embodiment, the plurality of spacers further includes a fourth spacer element disposed between the fourth lens and the fifth lens and in contact with the image-side surface of the fourth lens, wherein the radius of curvature R8 of the image-side surface of the fourth lens, the radius of curvature R9 of the object-side surface of the fifth lens, the inner diameter d4s of the object-side surface of the fourth spacer element and the inner diameter d4m of the image-side surface of the fourth spacer element satisfy: 5 < (R8 × R9) / (d4s × d4m) < 39.

[0020] In one embodiment, the inner diameter d5s of the object side of the fifth spacer element, the inner diameter d5m of the image side of the fifth spacer element, the radius of curvature R10 of the image side of the fifth lens, and the radius of curvature R11 of the object side of the sixth lens satisfy: 4<(d5s×d5m) / (R10×R11)<9.

[0021] In one embodiment, the inner diameter d0m of the rear end face of the lens barrel near the image side, the outer diameter D0m of the rear end face of the lens barrel near the image side, and the radius of curvature R12 of the image side surface of the sixth lens satisfy: 4<(d0m+D0m) / R12<10.

[0022] This application also provides an optical imaging system comprising: an imaging lens group consisting of 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; wherein the first lens has positive optical power, the second lens has negative optical power, the third and fourth lenses have different signs of optical power, the fifth and sixth lenses have different signs of optical power, the sixth lens has inflection points on both its object-side and image-side surfaces, and the refractive indices of the second and fourth lenses are both greater than 1.6; and a plurality of spacers, including those placed on the second lens... A second spacer element between the lens and the third lens and in contact with the image-side surface of the second lens; a third spacer element between the third lens and the fourth lens and in contact with the image-side surface of the third lens; and a fourth spacer element between the fourth lens and the fifth lens and in contact with the image-side surface of the fourth lens; and a lens barrel for accommodating the imaging lens group and the plurality of spacers; the radius of curvature R8 of the image-side surface of the fourth lens, the spacing EP23 between the image-side surface of the second spacer element and the object-side surface of the third spacer element along the optical axis, and the spacing EP34 between the image-side surface of the third spacer element and the object-side surface of the fourth spacer element along the optical axis satisfy: 11 <R8 / (EP23+EP34)<55。

[0023] On the other hand, the present application also provides an optical imaging system, which includes: an imaging lens group composed of 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 has a positive optical power, and the curvature radii of its object side and image side are both positive; the second lens has a negative optical power, and the curvature radii of its object side and image side are both positive; the signs of the optical powers of the third lens and the fourth lens are different, the curvature radius of the object side of the third lens is positive; the curvature radius of the image side of the fourth lens is positive; the fifth lens has a positive optical power, the curvature radius of its object side is positive, and the curvature radius of its image side is negative; the sixth lens has a negative optical power, both the object side and the image side of the sixth lens have an inflection point, the curvature radius of the object side of the sixth lens is negative, and the curvature radius of the image side is positive; and the refractive indices of the second lens and the fourth lens are both greater than 1.6; a plurality of spacer elements, including a second spacer element placed between the second lens and the third lens and in contact with the image side of the second lens, a third spacer element placed between the third lens and the fourth lens and in contact with the image side of the third lens, and a fourth spacer element placed between the fourth lens and the fifth lens and in contact with the image side of the fourth lens; and a lens barrel for accommodating the imaging lens group and the plurality of spacer elements; the curvature radius R8 of the image side of the fourth lens, the interval EP23 in the optical axis direction between the image side of the second spacer element and the object side of the third spacer element, and the interval EP34 in the optical axis direction between the image side of the third spacer element and the object side of the fourth spacer element satisfy: 11 < R8 / (EP23 + EP34) < 55.

[0024] In one embodiment, the plurality of spacer elements further includes a first spacer element placed between the first lens and the second lens and in contact with the image side of the first lens, and a fifth spacer element placed between the fifth lens and the sixth lens and in contact with the image side of the fifth lens. Among them, the optical imaging system satisfies: 0.5 < Dis / f < 2.0, where Dis is the outer diameter of the object side of the spacer element on the image side of the lens in the imaging lens group with an Abbe number greater than 50, and f is the effective focal length of the optical imaging system; where when i = 1, D1s represents the outer diameter of the object side of the first spacer element; when i = 2, D2s represents the outer diameter of the object side of the second spacer element; when i = 3, D3s represents the outer diameter of the object side of the third spacer element; when i = 4, D4s represents the outer diameter of the object side of the fourth spacer element; and when i = 5, D5s represents the outer diameter of the object side of the fifth spacer element.

[0025] In one embodiment, the plurality of spacer elements further includes a first spacer element disposed between the first lens and the second lens and in contact with the image side surface of the first lens, and a fifth spacer element disposed between the fifth lens and the sixth lens and in contact with the image side surface of the fifth lens, wherein the optical imaging system satisfies: 1 < Djm / EPD < 4, where Djm is the outer diameter of the image side surface of the spacer element on the image side surface of the lens with positive optical power in the imaging lens group, and EPD is the entrance pupil diameter of the optical imaging system; when j takes 1, D1m represents the outer diameter of the image side surface of the first spacer element; when j takes 2, D2m represents the outer diameter of the image side surface of the second spacer element; when j takes 3, D3m represents the outer diameter of the image side surface of the third spacer element; when j takes 4, D4m represents the outer diameter of the image side surface of the fourth spacer element; and when j takes 5, D5m represents the outer diameter of the image side surface of the fifth spacer element.

[0026] In one embodiment, the spacer element further includes a first spacer element disposed between the first lens and the second lens and in contact with the image side surface of the first lens; wherein the axial distance TD from the object side surface of the first lens to the image side surface of the sixth lens, the effective focal length f of the optical imaging system, the interval EP01 between the front end surface of the lens barrel near the object side and the object side surface of the first spacer element along the optical axis, and the inner diameter d0s of the front end surface of the lens barrel near the object side satisfy: 3 < (TD × f) / (EP01 × d0s) < 8.

[0027] In one embodiment, the spacer element further includes a first spacer element disposed between the first lens and the second lens and in contact with the image side surface of the first lens; wherein the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the inner diameter d1s of the object side surface of the first spacer element, and the inner diameter d1m of the image side surface of the first spacer element satisfy: 5 < |f1 × f2| / (d1s × d1m) < 12.

[0028] In one embodiment, at least two of the first lens to the fourth lens are meniscus lenses in the paraxial region.

[0029] In one embodiment, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: R2 > R1.

[0030] In one embodiment, the spacer element further includes a first spacer element disposed between the first lens and the second lens and in contact with the image side surface of the first lens; wherein 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 interval EP12 between the image side surface of the first spacer element and the object side surface of the second spacer element along the optical axis, and the maximum thickness CP2 of the second spacer element along the optical axis satisfy: 30 < (R3 + R4) / (EP12 + CP2) < 77.

[0031] In one embodiment, the radius of curvature R5 of the object side of the third lens, the radius of curvature R6 of the image side of the third lens, the inner diameter d2s of the object side of the second spacer element, and the inner diameter d3s of the object side of the third spacer element satisfy: 0 < |R6 / R5| × (d3s / d2s) < 6.

[0032] In one embodiment, the effective focal length f4 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: 2<|f4| / (d3m+D3m)<25.

[0033] In one embodiment, the spacer element further includes a fifth spacer element disposed between the fifth lens and the sixth lens and in contact with the image-side surface of the fifth lens; wherein the effective focal length f5 of the fifth lens, the maximum thickness CP4 of the fourth spacer element along the optical axis, and the spacing EP45 between the image-side surface of the fourth spacer element and the object-side surface of the fifth spacer element along the optical axis satisfy: 3 <f5 / (CP4+EP45)<8。

[0034] In one embodiment, the plurality of spacers further includes a first spacer element placed between the first lens and the second lens and in contact with the image-side surface of the first lens, and a fifth spacer element placed between the fifth lens and the sixth lens and in contact with the image-side surface of the fifth lens, wherein the effective focal length f1 of the first lens, the effective focal length f6 of the sixth lens, the spacing EP01 of the front end face of the lens barrel near the object side and the object side surface of the first spacer element along the optical axis direction and the maximum thickness CP5 of the fifth spacer element along the optical axis direction satisfy: 0.5 < (f1 + f6) / (EP01 + CP5) < 3.

[0035] In one embodiment, the spacer element further includes a fifth spacer element disposed between the fifth lens and the sixth lens 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 and the maximum thickness CP5 of the fifth spacer element along the optical axis satisfy: 1<|f5+f6| / CP5<16.

[0036] In one embodiment, the radius of curvature R8 of the image side of the fourth lens, the radius of curvature R9 of the object side of the fifth lens, the inner diameter d4s of the object side of the fourth spacer element, and the inner diameter d4m of the image side of the fourth spacer element satisfy: 5 < (R8 × R9) / (d4s × d4m) < 39.

[0037] In one embodiment, the spacer element further includes a fifth spacer element disposed between the fifth lens and the sixth lens and in contact with the image-side surface of the fifth lens; wherein the inner 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, 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 satisfy: 4<(d5s×d5m) / (R10×R11)<9.

[0038] In one embodiment, the inner diameter d0m of the rear end face of the lens barrel near the image side, the outer diameter D0m of the rear end face of the lens barrel near the image side, and the radius of curvature R12 of the image side surface of the sixth lens satisfy: 4<(d0m+D0m) / R12<10.

[0039] The optical imaging system provided in this application is a six-element lens with a large step difference. By rationally configuring the optical power of each lens, ultra-thin lenses can be achieved under the premise of good manufacturing feasibility, providing greater flexibility for the shape design of electronic devices such as mobile phones. By controlling the refractive index of the second and fourth lenses to be greater than 1.6, the direction of light can be adjusted, reducing stray light phenomena while eliminating chromatic aberration. Furthermore, by setting spacers between the lenses, the overall strength of the lens is ensured, enabling the lens to meet assembly and reliability requirements.

[0040] The optical imaging system provided in this application is a six-element lens with a large step difference. By controlling the effective focal length of the first lens and the sixth lens, it is beneficial to control the total length of the lens and ensure that the lens meets the requirements of ultra-thinness and miniaturization. Furthermore, by controlling the spacing along the optical axis between the front end face of the lens barrel near the object side and the object side side of the first spacer element, as well as the thickness of the fifth spacer element, the overall strength of the lens is ensured, so that the lens meets the assembly requirements and reliability requirements.

[0041] The optical imaging system provided in this application is a six-element lens with a large step difference. By adjusting the radius of curvature of the object side of the fourth lens, the spacing between the second and third spacers along the optical axis, and the spacing between the third and fourth spacers along the optical axis, it is beneficial to improve the steepness of the front light and the assembly stability, which can reduce the difficulty of lens forming and make the lens meet the reliability requirements.

[0042] The optical imaging system according to the present application satisfies: 11 < R8 / (EP23 + EP34) < 55, where R8 is the radius of curvature of the image side of the fourth lens, EP23 is the distance between the image side of the second spacer and the object side of the third spacer along the optical axis direction, and EP34 is the distance between the image side of the third spacer and the object side of the fourth spacer along the optical axis direction. Satisfying 11 < R8 / (EP23 + EP34) < 55 is beneficial to ensuring the assembly stability of the optical imaging system. The radius of curvature R8 of the object side of the fourth lens determines the thickness of the third spacer. The distance EP23 between the second spacer and the third spacer along the optical axis determines the edge thickness of the third lens. The distance EP34 between the third spacer and the fourth spacer along the optical axis determines the edge thickness of the fourth lens. This edge thickness determines the steepness of the front-end light rays and the radius of curvature of the fourth lens. EP23 and EP34 jointly affect the ease of lens forming and the assembly stability. When the conditional formula 11 < R8 / (EP23 + EP34) < 55 is satisfied, the smaller the radius of curvature R8 of the object side of the fourth lens, the better the assembly stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Other features, objects, and advantages of the present application will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0044] Figure 1 The structural layout diagram of an optical imaging system according to the present application and the schematic diagram of some parameters are shown;

[0045] Figures 2A to 2C The structural schematic diagram of the optical imaging system according to Embodiment 1 of the present application is shown;

[0046] Figures 3A to 3C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging system according to Embodiment 1 of the present application are respectively shown;

[0047] Figures 4A to 4C The structural schematic diagram of the optical imaging system according to Embodiment 2 of the present application is shown;

[0048] Figures 5A to 5C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging system according to Embodiment 2 of the present application are respectively shown;

[0049] Figures 6A to 6C The structural schematic diagram of the optical imaging system according to Embodiment 3 of the present application is shown; and

[0050] Figures 7A to 7C The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging system according to Embodiment 3 of the present application are shown. Detailed Implementation

[0051] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0052] 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.

[0053] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0054] In this article, curvature or paraxial curvature refers to the curvature of the region near the optical axis. If the curvature of a lens surface is positive and its location is not defined, it means that the curvature of the lens surface is positive at least in the paraxial region; if the curvature of a lens surface is negative and its location is not defined, it means that the curvature of the lens surface is negative 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.

[0055] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0056] 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.

[0057] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other. The following embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. For example, the lens groups (i.e., the first to sixth lenses), lens barrel structures, and spacer elements in the various embodiments of this application can be arbitrarily combined, and it is not limited to the lens group in one embodiment being combined only with the lens barrel structure, spacer elements, etc. of that embodiment.

[0058] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Figure 1 This diagram illustrates the structural layout and schematic diagram of some parameters of an optical imaging system according to this application. Those skilled in the art will understand that some parameters frequently used in the art, such as the center thickness CT1 of the first lens on the optical axis, are not shown. Figure 1 As shown in the figure, Figure 1 The present application only exemplarily illustrates some parameters of the lens barrel and spacer element of an optical imaging system to facilitate a better understanding of the invention. Figure 1 As shown, L represents the maximum height of the lens barrel along the optical axis; EP01 represents the distance between the front end face of the lens barrel near the object side and the object side face of the first spacer element along the optical axis; EP12 represents the distance between the image side face of the first spacer element and the object side face of the second spacer element along the optical axis; CP5 represents the maximum thickness of the fifth spacer element along the optical axis; D1s represents the outer diameter of the object side face of the first spacer element; d1s represents the inner diameter of the object side face of the first spacer element; D0s represents the outer diameter of the front end face of the lens barrel near the object side; d0s represents the inner diameter of the front end face of the lens barrel near the object side; D5m represents the outer diameter of the image side face of the fifth spacer element; d5m represents the inner diameter of the image side face of the fifth spacer element; D0m represents the outer diameter of the rear end face of the lens barrel near the image side; d0m represents the inner diameter of the rear end face of the lens barrel near the image side.

[0059] The features, principles and other aspects of this application are described in detail below.

[0060] An optical imaging system according to an exemplary embodiment of this application includes an imaging lens group and multiple spacer elements. The imaging lens group, along the optical axis from the object side to the image side, sequentially includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens has positive optical power, the second lens has negative optical power, the third lens has either positive or negative optical power, the fourth lens has either positive or negative optical power, the fifth lens has either positive or negative optical power, and the sixth lens has either positive or negative optical power. The third and fourth lenses have different signs of optical power, as do the fifth and sixth lenses. The sixth lens has inflection points on both its object-side and image-side surfaces, and the refractive indices of the second and fourth lenses are both greater than 1.6. By rationally configuring the optical power of each lens, ultra-thin lenses can be achieved while maintaining good manufacturing feasibility, providing greater flexibility in the design of mobile phones and other electronic devices. By controlling the refractive index of both the second and fourth lenses to be greater than 1.6, the direction of light can be adjusted, reducing stray light phenomena while eliminating chromatic aberration.

[0061] In an exemplary embodiment, the optical imaging system further includes a lens barrel for housing an imaging lens group and a plurality of spacer elements.

[0062] In an exemplary embodiment, at least two of the first to fourth lenses are meniscus lenses. More specifically, at least two of the first to fourth lenses are meniscus lenses in the paraxial region. Lenses of different shapes have different focal lengths and different light processing effects. An imaging lens group is a superposition of different lens surfaces. By superimposing the focal lengths of different lens surfaces, a certain imaging effect is achieved. Meniscus lenses can stably increase the imaging size, effectively shortening the overall lens length while ensuring good manufacturability, realizing the ultra-thin characteristics of large image sensor lenses and meeting the imaging requirements of the lens. Ensuring good manufacturability of the lenses in the mold is also a prerequisite for improving performance and yield.

[0063] In an exemplary embodiment, the plurality of spacer elements may include a first spacer element disposed between a first lens and a second lens and in contact with the image-side surface of the first lens, a second spacer element disposed between a second lens and a third lens and in contact with the image-side surface of the second lens, a third spacer element disposed between a third lens and a fourth lens and in contact with the image-side surface of the third lens, a fourth spacer element disposed between a fourth lens and a fifth lens and in contact with the image-side surface of the fourth lens, and a fifth spacer element disposed between a fifth lens and a sixth lens and in contact with the image-side surface of the fifth lens.

[0064] It should be understood that the present application does not specifically limit the number of spacer elements. Any number of spacer elements can be included between any two lenses, and the entire optical imaging system can also include any number of spacer elements. The spacer elements help the optical imaging system intercept redundant catadioptric light paths, reducing the generation of stray light and ghost images. Adding auxiliary supports between the spacer elements and the lens barrel is beneficial to improving problems such as poor assembly stability and low performance yield due to large step differences between lenses.

[0065] In an exemplary embodiment, the optical imaging system according to the present application can satisfy: 0.5 < (f1 + f6) / (EP01 + CP5) < 3, where f1 is the effective focal length of the first lens, f6 is the effective focal length of the sixth lens, EP01 is the distance along the optical axis between the front end face of the lens barrel near the object side and the object side surface of the first spacer element, and CP5 is the maximum thickness of the fifth spacer element along the optical axis. Satisfying 0.5 < (f1 + f6) / (EP01 + CP5) < 3 and controlling the effective focal lengths of the first lens and the sixth lens is beneficial to controlling the total length of the lens, ensuring that the lens meets the requirements of ultra-thinness and miniaturization. By further controlling the distance along the optical axis between the front end face of the lens barrel near the object side and the object side surface of the first spacer element and the thickness of the fifth spacer element, the overall strength of the lens is guaranteed, enabling the lens to meet the assembly requirements and reliability requirements.

[0066] In an exemplary embodiment, the optical imaging system according to the present application can satisfy: 0.5 < Dis / f < 2.0, where Dis is the outer diameter of the object side surface of the spacer element on the image side of the lens with an Abbe number greater than 50 in the imaging lens group; f is the effective focal length of the optical imaging system; exemplarily, when i = 1, D1s represents the outer diameter of the object side surface of the first spacer element; when i = 2, D2s represents the outer diameter of the object side surface of the second spacer element; when i = k3, D3s represents the outer diameter of the object side surface of the third spacer element; when i = 4, D4s represents the outer diameter of the object side surface of the fourth spacer element; when i = 5, D5s represents the outer diameter of the object side surface of the fifth spacer element. Since it is necessary to control the overall chromatic aberration of the lens in the early stage of the design of the optical imaging system, materials with high Abbe numbers are reasonably selected, which can save the cost of the lens while meeting the performance requirements. The optical imaging system according to the present application satisfies 0.5 < Dis / f < 2.0. By controlling the ratio of Dis to the effective focal length, the overall thickness of the lens can be guaranteed, leaving a large space for the module design.

[0067] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 1 < Djm / EPD < 4, where Djm is the outer diameter of the image side of the spacer element on the image side of the lens with positive optical power in the imaging lens group; EPD is the entrance pupil diameter of the optical imaging system;示例性地, when j = 1, D1m represents the outer diameter of the image side of the first spacer element; when j = 2, D2m represents the outer diameter of the image side of the second spacer element; when j = 3, D3m represents the outer diameter of the image side of the third spacer element; when j = 4, D4m represents the outer diameter of the image side of the fourth spacer element; and when j = 5, D5m represents the outer diameter of the image side of the fifth spacer element. When the lens has positive optical power, it is beneficial to the convergence of light rays in each field of view of the imaging system. By reasonably setting the optical power of the lens, good processability of the lens can be ensured. Satisfying 1 < Djm / EPD < 4, by controlling the ratio of Djm (the outer diameter of the image side of the spacer element on the image side of the lens with positive optical power) to the entrance pupil diameter EPD, the steepness of the light rays can be effectively controlled, the optical parameters of the lens can be ensured to be stable, and in addition, the stray light of the lens can be effectively improved and the imaging quality can be enhanced.

[0068] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 3 < (TD × f) / (EP01 × d0s) < 8, where TD is the axial distance from the object side of the first lens to the image side of the sixth lens, f is the effective focal length of the optical imaging system, EP01 is the distance along the optical axis between the front end face of the lens barrel near the object side and the object side of the first spacer element, and d0s is the inner diameter of the front end face of the lens barrel near the object side. Satisfying 3 < (TD × f) / (EP01 × d0s) < 8, by controlling the product of the axial distance TD from the object side of the first lens to the image side of the sixth lens and the effective focal length f of the optical imaging system, it is beneficial to ensure the height of the lens. Through the distance EP01 along the optical axis between the front end face of the lens barrel near the object side and the object side of the first spacer element and the inner diameter d0s of the front end face of the lens barrel, it is beneficial to ensure the wall thickness of the front end of the lens barrel and the length of the top surface support. Generally, when the outer shape is determined, the longer the top surface support is, the more beneficial it is for assembly. In addition, a thicker wall thickness at the front end of the lens barrel can also ensure the stability of the lens barrel processing and molding, and avoid flocculent stray light caused by too thin holes formed and insufficient filling.

[0069] In an exemplary embodiment, the optical imaging system according to this application satisfies: 5 < |f1×f2| / (d1s×d1m) < 12, where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, d1s is the inner diameter of the object-side surface of the first spacer element, and d1m is the inner diameter of the image-side surface of the first spacer element. Satisfying 5 < |f1×f2| / (d1s×d1m) < 12 allows for adjustment of the light convergence between the first and second lenses by controlling their effective focal lengths. Controlling the inner diameter of the first spacer element effectively ensures relative optical illumination and avoids stray light risks transmitted through the edge of the effective diameter. Furthermore, stray light on the inner end face of the spacer element can be avoided through extinction or structural adjustments, thus improving the overall imaging quality of the lens.

[0070] In an exemplary embodiment, the optical imaging system according to this application satisfies: R2 > R1, where R1 is the radius of curvature of the object-side surface of the first lens, and R2 is the radius of curvature of the image-side surface of the first lens. More specifically, R1 and R2 may further satisfy: R2 > R1 > 0. Satisfying R2 > R1, by controlling the relationship between the radii of curvature of the object-side and image-side surfaces of the first lens, is beneficial for optimizing the shape of the first lens, and at the same time, it can optimize the manufacturability of the first lens.

[0071] In an exemplary embodiment, the optical imaging system according to this application satisfies: 30 < (R3 + R4) / (EP12 + CP2) < 77, where 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, EP12 is the distance between the image-side surface of the first spacer element and the object-side surface of the second spacer element along the optical axis, and CP2 is the maximum thickness of the second spacer element along the optical axis. Satisfying 30 < (R3 + R4) / (EP12 + CP2) < 77 allows for effective control of the lens shape through the radii of curvature of the object-side and image-side surfaces of the second lens. The distance EP12 between the image-side and object-side surfaces of the first and second spacers elements along the optical axis also controls the edge thickness of the second lens, effectively ensuring its manufacturability. Furthermore, controlling the thickness of the second spacer element allows for adjustment of its thickness based on actual trial assembly to optimize field curvature and ensure stable performance of the optical imaging system.

[0072] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0 < |R6 / R5| × (d3s / d2s) < 6, where R5 is the radius of curvature of the object side surface of the third lens, R6 is the radius of curvature of the image side surface of the third lens, d2s is the inner diameter of the object side surface of the second spacer element, and d3s is the inner diameter of the object side surface of the third spacer element. Satisfying 0 < |R6 / R5| × (d3s / d2s) < 6 is beneficial to meeting the requirements of structural control. Among them, the ratio of the radius of curvature R5 of the object side surface of the third lens to the radius of curvature R6 of the image side surface of the third lens can affect the outer diameter sizes of the object side surfaces of the second spacer element and the third spacer element. The difference between the inner and outer diameters of the spacer element determines the toroidal width of the object side surface of the spacer element, which is beneficial to ensuring the assembly stability of the optical imaging system. The longer the bearing length, the better the assembly stability. Similarly, the position of the spacer element can effectively block the stray light passing through the edge of the effective diameter, improving the imaging quality.

[0073] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 2 < |f4| / (d3m + D3m) < 25, where f4 is the effective focal length of the fourth lens, d3m is the inner diameter of the image side surface of the third spacer element, and D3m is the outer diameter of the image side surface of the third spacer element. Satisfying 2 < |f4| / (d3m + D3m) < 25 is beneficial to controlling the interception of the outgoing light of the fourth lens by the fourth spacer element. Under the condition of ensuring the lens illuminance, the more light is blocked, the better the stray light improvement effect, and the higher the imaging quality of the lens.

[0074] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 3 < f5 / (CP4 + EP45) < 8, where f5 is the effective focal length of the fifth lens, CP4 is the maximum thickness of the fourth spacer element along the optical axis direction, and EP45 is the interval between the image side surface of the fourth spacer element and the object side surface of the fifth lens along the optical axis direction. Satisfying 3 < f5 / (CP4 + EP45) < 8 is beneficial to controlling the incident angle of off-axis field light on the imaging surface, increasing the matching with the photosensitive element and the band-pass filter; in addition, it is also beneficial to controlling the thickness ratio and surface shape of the fifth lens, ensuring that the fifth lens has good processing feasibility.

[0075] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 11 < R8 / (EP23 + EP34) < 55, where R8 is the radius of curvature of the image-side surface of the fourth lens, EP23 is the axial interval between the image-side surface of the second spacer and the object-side surface of the third spacer, and EP34 is the axial interval between the image-side surface of the third spacer and the object-side surface of the fourth spacer. Satisfying 11 < R8 / (EP23 + EP34) < 55 is beneficial to meeting the requirements for the assembly stability of the optical imaging system. The radius of curvature R8 of the object-side surface of the fourth lens determines the thickness of the third spacer. The axial interval EP23 between the second spacer and the third spacer determines the edge thickness of the third lens. The axial interval EP34 between the third spacer and the fourth spacer determines the edge thickness of the fourth lens. This edge thickness determines the steepness of the front-end light rays and the radius of curvature of the fourth lens. EP23 and EP34 jointly affect the ease of lens forming and the assembly stability. When the condition 11 < R8 / (EP23 + EP34) < 55 is satisfied, the smaller the radius of curvature R8 of the object-side surface of the fourth lens, the better the assembly stability.

[0076] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 1 < |f5 + f6| / CP5 < 16, where f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and CP5 is the maximum thickness of the fifth spacer along the optical axis. The effective focal lengths of the fifth lens and the sixth lens determine the surface shapes of the lenses before and after the fifth spacer, and also determine the thickness and strength of the fifth spacer. Therefore, satisfying 1 < |f5 + f6| / CP5 < 16 can, on the one hand, optimize the performance field curvature by adjusting the thickness of the fifth spacer, and on the other hand, block the back-end stray light reflected from the sixth lens to the fifth spacer, improving the performance yield and imaging quality.

[0077] In an exemplary embodiment, the optical imaging system according to this application satisfies: 5 < (R8 × R9) / (d4s × d4m) < 39, where R8 is the radius of curvature of the image-side surface of the fourth lens, R9 is the radius of curvature of the object-side surface of the fifth lens, d4s is the inner diameter of the object-side surface of the fourth spacer element, and d4m is the inner diameter of the image-side surface of the fourth spacer element. Satisfying 5 < (R8 × R9) / (d4s × d4m) < 39 facilitates controlling the smoothness of light by controlling the radius of curvature of the image-side surface of the fourth lens and the radius of curvature of the object-side surface of the fifth lens, thus ensuring the stability of the lens surface shape. Furthermore, since the step difference between the fourth and fifth lenses in the optical imaging system is also relatively large, the auxiliary support provided by the fourth spacer element helps ensure assembly stability. Exemplarily, the fourth spacer element can be a plastic spacer ring. While ensuring the strength of the fourth spacer element, controlling the inner diameter position of the image side and object side of the fourth spacer element is beneficial to optimizing stray light reflected from the filter to the lower end face of the fourth spacer element. Overall, this is beneficial to structural stability and can also improve imaging quality.

[0078] In an exemplary embodiment, the optical imaging system according to this application satisfies: 4 < (d5s × d5m) / (R10 × R11) < 9, where d5s is the inner diameter of the object-side surface of the fifth spacer element, d5m is the inner diameter of the image-side surface of the fifth spacer element, R10 is the radius of curvature of the image-side surface of the fifth lens, and R11 is the radius of curvature of the object-side surface of the sixth lens. Satisfying 4 < (d5s × d5m) / (R10 × R11) < 9 allows for the control of light smoothness by adjusting the radius of curvature of the image-side surface of the fifth lens and the object-side surface of the sixth lens, thus ensuring surface stability. Furthermore, the fifth and sixth lenses are also the locations with the largest difference in image size between the lenses; the fifth spacer element is used for auxiliary support to ensure assembly stability. The fifth spacer element can be a plastic spacer ring. Additionally, while ensuring the strength of the fifth spacer element, controlling the inner diameter positions of the image-side and object-side surfaces of the fifth spacer element helps optimize stray light reflected from the color filter to the lower surface of the fifth spacer element.

[0079] In an exemplary embodiment, the optical imaging system according to this application satisfies: 4 < (d0m + D0m) / R12 < 10, where d0m is the inner diameter of the rear end face of the lens barrel near the image side, D0m is the outer diameter of the rear end face of the lens barrel near the image side, and R12 is the radius of curvature of the image side surface of the sixth lens. Satisfying 4 < (d0m + D0m) / R12 < 10, by controlling the inner and outer diameters of the rear end face of the lens barrel, helps to ensure the large image plane characteristics of the lens and also helps to ensure that the width of the rear end face of the lens barrel meets the requirements of internal testing. In addition, the sixth lens is the lens with the largest outer diameter among the 6P large image plane lenses, which has a greater molding risk and a greater risk of stray light generation. By controlling this condition, the surface shape of the sixth lens can be effectively controlled, ensuring that the surface shape curve of the image plane is smooth, the wavefront curve of the sol during injection molding is relatively smooth, there is no convergence and encapsulation phenomenon, reducing the risk of weld lines, thereby reducing the risk of stray light and appearance problems at the weld lines.

[0080] In exemplary embodiments, the optical imaging system described above may further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface. The optical imaging system according to the above embodiments of this application may employ multiple lenses, such as the six lenses mentioned above. By rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis spacing between lenses, incident light can be effectively converged, the overall optical length of the imaging lens can be reduced, and the manufacturability of the imaging lens can be improved, making the optical imaging system more conducive to manufacturing.

[0081] In embodiments of this application, at least one of the mirror surfaces of each lens is an aspherical mirror surface; that is, at least one mirror surface from the object-side surface of the first lens to the image-side surface of the sixth lens is an aspherical mirror surface. An aspherical lens is characterized by a continuously changing curvature from the lens center to the lens periphery. Unlike a spherical lens, which has a constant curvature from the lens center to the lens periphery, an aspherical lens has better curvature radius characteristics, offering advantages in improving distortion aberrations and astigmatism. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality. Optionally, the object-side surface and image-side surface of each of the first, second, third, fourth, fifth, and sixth lenses are both aspherical mirror surfaces.

[0082] Specific embodiments of the optical imaging system applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

[0083] Example 1

[0084] The following is for reference Figures 2A to 3C The optical imaging system 1001, optical imaging system 1002 and optical imaging system 1003 according to Embodiment 1 of this application are described. Figures 2A to 2CSchematic diagrams of optical imaging systems 1001, 1002 and 1003 according to Embodiment 1 of this application are shown respectively.

[0085] like Figures 2A to 2C As shown, optical imaging systems 1001, 1002 and 1003 each include a lens barrel P0, imaging lens groups E1 to E6 and multiple spacer elements P1 to P5.

[0086] like Figures 2A to 2C As shown, optical imaging systems 1001, 1002, and 1003 employ the same imaging lens group, which, from the object side to the image side, sequentially 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. Specifically, the first lens E1 has positive optical power and has an object-side surface S1 and an image-side surface S2. The second lens E2 has negative optical power and has an object-side surface S3 and an image-side surface S4. The third lens E3 has positive optical power and has an object-side surface S5 and an image-side surface S6. The fourth lens E4 has negative optical power and has an object-side surface S7 and an image-side surface S8. The fifth lens E5 has positive optical power and has an object-side surface S9 and an image-side surface S10. The sixth lens E6 has negative optical power and has an object-side surface S11 and an image-side surface S12. The filter E7 (not shown) has an object side surface S13 (not shown) and an image side surface S14 (not shown). Light from the object passes through each surface S1 to S14 in sequence and is finally imaged on the imaging surface S15 (not shown).

[0087] Table 1 shows the basic parameters of the imaging lens groups of optical imaging systems 1001, 1002 and 1003 of Embodiment 1, wherein the units of radius of curvature, thickness and effective focal length are millimeters (mm).

[0088]

[0089] Table 1

[0090] In this example, optical imaging systems 1001, 1002, and 1003 also have the following basic parameters: the distance TD between the object side of the first lens and the image side of the sixth lens on the optical axis is 5.342 mm; half the diagonal length ImgH of the effective pixel area on the imaging surface of the optical imaging system is 4.75 mm; the effective focal length f of the optical imaging system is 5.38 mm; and the entrance pupil diameter EPD of the optical imaging system is 3.20 mm.

[0091] In Embodiment 1, the object-side surface and image-side surface 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:

[0092]

[0093] Where x is the distance vector from the vertex of the aspherical surface at a height 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 mirror S1-S12 in Example 1. 10 A 12 A 14 A 16 A 18 and A 20 .

[0094]

[0095] Table 2

[0096] like Figures 2A to 2C As shown, the optical imaging systems 1001, 1002, and 1003 each include a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5. Specifically, the first spacer element P1 is disposed between the first lens E1 and the second lens E2 and contacts the image-side surface of the first lens E1; the second spacer element P2 is disposed between the second lens E2 and the third lens E3 and contacts the image-side surface of the second lens E2; the third spacer element P3 is disposed between the third lens E3 and the fourth lens E4 and contacts the image-side surface of the third lens E3; the fourth spacer element P4 is disposed between the fourth lens E4 and the fifth lens E5 and contacts the image-side surface of the fourth lens E4; and the fifth spacer element P5 is disposed between the fifth lens E5 and the sixth lens E6 and contacts the image-side surface of the fifth lens E5. The aforementioned multiple spacer elements can block excess external light from entering, allowing the lens to better support the lens barrel and enhancing the structural stability of optical imaging systems 1001, 1002, and 1003.

[0097] Table 3 shows the basic parameters of the spacer elements and lens barrels of the optical imaging systems 1001, 1002 and 1003 of Embodiment 1. The unit of each parameter in Table 3 is millimeters (mm).

[0098]

[0099]

[0100] Table 3

[0101] Figure 3A The on-axis chromatic aberration curves of optical imaging systems 1001, 1002 and 1003 of Embodiment 1 are shown, which represent the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 3B Astigmatism curves of optical imaging systems 1001, 1002 and 1003 of Embodiment 1 are shown, representing meridional image plane curvature and sagittal image plane curvature. Figure 3C The distortion curves of optical imaging systems 1001, 1002, and 1003 of Embodiment 1 are shown, representing the distortion magnitude values ​​corresponding to different image heights. According to... Figures 3A to 3C It can be seen that the optical imaging system 1001, optical imaging system 1002 and optical imaging system 1003 given in Example 1 can achieve good imaging quality.

[0102] Example 2

[0103] The following is for reference Figures 4A to 5C The optical imaging system 2001, optical imaging system 2002, and optical imaging system 2003 according to Embodiment 2 of this application are described. In this embodiment and the following embodiments, for the sake of brevity, some descriptions similar to those in Embodiment 1 will be omitted. Figures 4A to 4C Schematic diagrams of optical imaging systems 2001, 2002 and 2003 according to Embodiment 2 of this application are shown respectively.

[0104] like Figures 4A to 4C As shown, optical imaging systems 2001, 2002 and 2003 each include a lens barrel P0, imaging lens groups E1 to E6 and multiple spacer elements P1 to P5.

[0105] like Figures 4A to 4CAs shown, optical imaging systems 2001, 2002, and 2003 employ the same imaging lens group, which, from the object side to the image side, sequentially 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. Specifically, the first lens E1 has positive optical power and has an object-side surface S1 and an image-side surface S2. The second lens E2 has negative optical power and has an object-side surface S3 and an image-side surface S4. The third lens E3 has negative optical power and has an object-side surface S5 and an image-side surface S6. The fourth lens E4 has positive optical power and has an object-side surface S7 and an image-side surface S8. The fifth lens E5 has positive optical power and has an object-side surface S9 and an image-side surface S10. The sixth lens E6 has negative optical power and has an object-side surface S11 and an image-side surface S12. The filter E7 (not shown) has an object side surface S13 (not shown) and an image side surface S14 (not shown). Light from the object passes through each surface S1 to S14 in sequence and is finally imaged on the imaging surface S15 (not shown).

[0106] In this example, optical imaging systems 2001, 2002, and 2003 also have the following basic parameters: the distance TD between the object side of the first lens and the image side of the sixth lens on the optical axis is 5.185 mm; half the diagonal length of the effective pixel area on the imaging surface of the optical imaging system, ImgH, is 4.75 mm; the effective focal length f of the optical imaging system is 5.57 mm; and the entrance pupil diameter EPD of the optical imaging system is 3.01 mm.

[0107] Table 4 shows the basic parameters of the imaging lens groups of optical imaging systems 2001, 2002, and 2003 in Embodiment 2, wherein the units of radius of curvature, thickness, and effective focal length are millimeters (mm). Table 5 shows the higher-order coefficients that can be used for each aspherical mirror in Embodiment 2, wherein each aspherical surface shape can be defined by formula (1) given in Embodiment 1 above.

[0108]

[0109] Table 4

[0110]

[0111]

[0112] Table 5

[0113] like Figures 4A to 4CAs shown, the optical imaging systems 2001, 2002, and 2003 each include a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5. Specifically, the first spacer element P1 is disposed between the first lens E1 and the second lens E2 and contacts the image-side surface of the first lens E1; the second spacer element P2 is disposed between the second lens E2 and the third lens E3 and contacts the image-side surface of the second lens E2; the third spacer element P3 is disposed between the third lens E3 and the fourth lens E4 and contacts the image-side surface of the third lens E3; the fourth spacer element P4 is disposed between the fourth lens E4 and the fifth lens E5 and contacts the image-side surface of the fourth lens E4; and the fifth spacer element P5 is disposed between the fifth lens E5 and the sixth lens E6 and contacts the image-side surface of the fifth lens E5. The aforementioned multiple spacer elements can block excess external light from entering, allowing the lens to better support the lens barrel and enhancing the structural stability of optical imaging systems 2001, 2002, and 2003.

[0114] Table 6 shows the basic parameters of the spacer elements and lens barrels of optical imaging systems 2001, 2002 and 2003 of Embodiment 2. The unit of each parameter in Table 6 is millimeters (mm).

[0115]

[0116]

[0117] Table 6

[0118] Figure 5A The on-axis chromatic aberration curves of optical imaging systems 2001, 2002 and 2003 of Embodiment 2 are shown, which indicate the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 5B Astigmatism curves of optical imaging systems 2001, 2002 and 2003 of Embodiment 2 are shown, representing meridional image plane curvature and sagittal image plane curvature. Figure 5C The distortion curves of optical imaging systems 2001, 2002, and 2003 of Embodiment 2 are shown, representing the distortion magnitude values ​​corresponding to different image heights. According to... Figures 5A to 5C It can be seen that the optical imaging system 2001, optical imaging system 2002 and optical imaging system 2003 given in Example 2 can achieve good imaging quality.

[0119] Example 3

[0120] The following is for reference Figures 6A to 7CThe optical imaging system 3001, optical imaging system 3002 and optical imaging system 3003 according to Embodiment 3 of this application are described. Figures 6A to 6B Schematic diagrams of optical imaging systems 3001, 3002 and 3003 according to Embodiment 3 of this application are shown respectively.

[0121] like Figures 6A to 6C As shown, optical imaging systems 3001, 3002 and 3003 each include a lens barrel P0, imaging lens groups E1 to E6 and multiple spacer elements P1 to P5.

[0122] like Figures 6A to 6C As shown, optical imaging systems 3001, 3002, and 3003 employ the same imaging lens group, which, from the object side to the image side, sequentially 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. Specifically, the first lens E1 has positive optical power and has an object-side surface S1 and an image-side surface S2. The second lens E2 has negative optical power and has an object-side surface S3 and an image-side surface S4. The third lens E3 has positive optical power and has an object-side surface S5 and an image-side surface S6. The fourth lens E4 has negative optical power and has an object-side surface S7 and an image-side surface S8. The fifth lens E5 has positive optical power and has an object-side surface S9 and an image-side surface S10. The sixth lens E6 has negative optical power and has an object-side surface S11 and an image-side surface S12. The filter E7 (not shown) has an object side surface S13 (not shown) and an image side surface S14 (not shown). Light from the object passes through each surface S1 to S14 in sequence and is finally imaged on the imaging surface S15 (not shown).

[0123] In this example, optical imaging systems 3001, 3002, and 3003 also have the following basic parameters: the distance TD between the object side of the first lens and the image side of the sixth lens on the optical axis is 5.242 mm; half the diagonal length of the effective pixel area ImgH on the imaging surface of the optical imaging system is 4.74 mm; the effective focal length f of the optical imaging system is 5.24 mm; and the entrance pupil diameter EPD of the optical imaging system is 2.86 mm.

[0124] Table 7 shows the basic parameters of the imaging lens groups of optical imaging systems 3001, 3002, and 3003 in Embodiment 3, wherein the units of radius of curvature, thickness, and effective focal length are millimeters (mm). Table 8 shows the higher-order coefficients that can be used for each aspherical mirror in Embodiment 3, wherein each aspherical surface shape can be defined by formula (1) given in Embodiment 1 above.

[0125]

[0126] Table 7

[0127]

[0128] Table 8

[0129] like Figures 6A to 6C As shown, the optical imaging systems 3001, 3002, and 3003 each include a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, and a fifth spacer element P5. Specifically, the first spacer element P1 is disposed between the first lens E1 and the second lens E2 and contacts the image-side surface of the first lens E1; the second spacer element P2 is disposed between the second lens E2 and the third lens E3 and contacts the image-side surface of the second lens E2; the third spacer element P3 is disposed between the third lens E3 and the fourth lens E4 and contacts the image-side surface of the third lens E3; the fourth spacer element P4 is disposed between the fourth lens E4 and the fifth lens E5 and contacts the image-side surface of the fourth lens E4; and the fifth spacer element P5 is disposed between the fifth lens E5 and the sixth lens E6 and contacts the image-side surface of the fifth lens E5. The aforementioned multiple spacer elements can block excess external light from entering, allowing the lens to better support the lens barrel and enhancing the structural stability of optical imaging systems 3001, 3002, and 3003.

[0130] Table 9 shows the basic parameters of the spacer elements and lens barrels of the optical imaging systems 3001, 3002 and 3003 of Embodiment 3. The unit of each parameter in Table 9 is millimeters (mm).

[0131] Example parameters Optical Imaging System 3001 Optical Imaging System 3002 Optical Imaging System 3003 d1s 2.657 2.634 2.592 d1m 2.657 2.634 2.592 D1s 3.927 3.745 4.726 D1m 3.927 3.745 4.726 d2s 2.394 2.417 2.378 d3s 2.797 2.829 2.750 d3m 2.797 2.829 2.750 D3s 4.456 4.263 5.062 D3m 4.456 4.263 5.062 d4s 4.023 4.173 3.939 d4m 4.023 4.173 3.939 D4m 8.277 7.976 7.742 d5s 5.939 6.203 6.155 d5m 5.939 6.203 6.155 D5s 9.220 9.019 8.895 D5m 9.220 9.019 8.895 d0s 4.083 4.096 4.083 d0m 9.745 9.554 9.593 D0m 10.767 10.556 9.881 EP01 1.037 1.063 1.243 EP12 0.451 0.445 0.463 CP2 0.018 0.018 0.024 EP23 0.414 0.419 0.418 EP34 0.740 0.785 0.744 CP4 0.037 0.040 0.041 EP45 0.915 0.932 0.928 CP5 0.040 0.037 0.041

[0132] Table 9

[0133] Figure 7A The on-axis chromatic aberration curves of optical imaging systems 3001, 3002 and 3003 of Embodiment 3 are shown, which indicate the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 7B Astigmatism curves of optical imaging systems 3001, 3002 and 3003 of Embodiment 3 are shown, representing meridional image plane curvature and sagittal image plane curvature. Figure 7C The distortion curves of optical imaging systems 3001, 3002, and 3003 of Embodiment 3 are shown, representing the distortion magnitude values ​​corresponding to different image heights. According to... Figures 7A to 7CIt can be seen that the optical imaging system 3001, optical imaging system 3002 and optical imaging system 3003 given in Example 3 can achieve good imaging quality.

[0134] In summary, the optical imaging systems 1001, 1002, 1003, 2001, 2002, 2003, 3001, 3002 and 3003 of Examples 1 to 3 satisfy the relationships shown in Table 10.

[0135] Conditional / Optical Imaging System 1001 1002 1003 2001 2002 2003 3001 3002 3003 (f1+f6) / (EP01+CP5) 1.55 1.54 1.40 1.09 1.11 1.14 2.21 2.16 1.85 (TD×f) / (EP01×d0s) 6.10 5.60 4.63 6.70 6.67 6.58 6.48 6.30 5.41 |f1×f2| / (d1s×d1m) 6.07 6.20 6.35 6.48 6.40 6.52 9.96 10.14 10.47 (R3+R4) / (EP12+CP2) 33.76 37.16 37.31 32.06 30.85 30.96 75.86 76.76 72.98 |R6 / R5|×(d3s / d2s) 5.08 5.18 5.09 0.92 0.89 0.86 0.04 0.04 0.04 |f4| / (d3m+D3m) 4.69 4.69 4.68 23.12 24.98 21.38 2.55 2.61 2.37 f5 / (CP4+EP45) 3.82 3.86 3.72 6.95 7.26 7.26 3.18 3.11 3.12 R8 / (EP23+EP34) 20.49 19.30 20.24 11.85 11.88 12.10 54.38 52.09 53.97 |f5+f6| / CP5 1.68 1.87 1.84 3.06 3.12 3.39 14.73 15.93 14.37 (R8×R9) / (d4s×d4m) 6.99 6.50 6.50 5.76 6.40 6.66 37.09 34.46 38.67 (d5s×d5m) / (R10×R11) 8.53 8.14 8.14 6.36 6.21 6.36 5.02 5.47 5.39 (d0m+D0m) / R12 6.72 6.65 6.65 4.18 4.22 4.22 9.52 9.33 9.03 D1s / f 0.76 0.78 0.93 0.74 0.79 0.86 0.75 0.72 0.90 D3s / f 1.00 0.99 1.00 0.97 0.86 1.13 0.85 0.81 0.97 D5s / f 1.44 1.50 1.50 1.39 1.40 1.39 1.76 1.72 1.70 D1m / EPD 1.28 1.32 1.57 1.36 1.46 1.60 1.37 1.31 1.65 D3m / EPD 1.69 1.67 1.69 / / / 1.56 1.49 1.77 D4m / EPD / / / 2.42 2.42 2.39 / / / D5m / EPD 2.44 2.53 2.53 2.59 2.63 2.60 3.22 3.15 3.11

[0136] Table 10

[0137] This application also provides an imaging device, whose electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device can be a stand-alone 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 imaging system described above.

[0138] 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 in that, include: An imaging lens group comprises 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 lens has positive optical power, with a convex object side and a concave image side. The second lens has negative optical power, with a convex object side and a concave image side. The third and fourth lenses have different signs of optical power; the third lens has a convex object side; the fourth lens has a concave image side. The fifth lens has positive optical power, with both its object and image sides being convex. The sixth lens has negative optical power, with inflection points on both its object and image sides, and both its object and image sides being concave. The refractive indices of the second and fourth lenses are both greater than 1.

6. Multiple spacer elements, including a second spacer element placed between the second lens and the third lens and in contact with the image side of the second lens, a third spacer element placed between the third lens and the fourth lens and in contact with the image side of the third lens, and a fourth spacer element placed between the fourth lens and the fifth lens and in contact with the image side of the fourth lens; as well as A lens barrel for housing the imaging lens group and the plurality of spacer elements; The optical imaging system has six lenses with optical power. The radius of curvature R8 of the image side of the fourth lens, the spacing EP23 between the image side of the second spacer and the object side of the third spacer along the optical axis, and the spacing EP34 between the image side of the third spacer and the object side of the fourth spacer along the optical axis satisfy: 11.85≤R8 / (EP23+EP34)≤54.

38.

2. The optical imaging system according to claim 1, characterized in that, The plurality of spacers further includes a first spacer element disposed between the first lens and the second lens and in contact with the image-side surface of the first lens, and a fifth spacer element disposed between the fifth lens and the sixth lens and in contact with the image-side surface of the fifth lens, wherein, Dis is the outer diameter of the object side of the spacer element on the image side of the lens with an Abbe number greater than 50 in the imaging lens group, and f is the effective focal length of the optical imaging system. Where i is 1, D1s represents the outer diameter of the object side of the first spacer element, and D1s and f satisfy: 0.72≤D1s / f≤0.93; When i is 3, D3s represents the outer diameter of the object side of the third spacer element, and D3s and f satisfy: 0.81 ≤ D3s / f ≤ 1.13; and When i is 5, D5s represents the outer diameter of the object side of the fifth spacer element, and D5s and f satisfy: 1.39≤D5s / f≤1.

76.

3. The optical imaging system according to claim 1, characterized in that, The plurality of spacers further includes a first spacer element disposed between the first lens and the second lens and in contact with the image-side surface of the first lens, and a fifth spacer element disposed between the fifth lens and the sixth lens and in contact with the image-side surface of the fifth lens, wherein, Djm is the outer diameter of the image-side surface of the spacer element of the lens with positive optical power in the imaging lens group, and EPD is the entrance pupil diameter of the optical imaging system. Where j is 1, D1m represents the outer diameter of the image side of the first spacer element, and D1m and EPD satisfy: 1.28≤D1m / EPD≤1.65; When j is 3, D3m represents the outer diameter of the image side of the third spacer element, and D3m and EPD satisfy: 1.49≤D3m / EPD≤1.77; When j is 4, D4m represents the outer diameter of the image-side surface of the fourth spacer element, and D4m and EPD satisfy: 2.39 ≤ D4m / EPD ≤ 2.42; and When j is 5, D5m represents the outer diameter of the image side of the fifth spacer element, and D5m and EPD satisfy: 2.44≤D5m / EPD≤3.

22.

4. The optical imaging system according to claim 1, characterized in that, The spacer element further includes a first spacer element disposed between the first lens and the second lens and in contact with the image-side surface of the first lens; wherein, The axial distance TD between the object side surface of the first lens and the image side surface of the sixth lens, the effective focal length f of the optical imaging system, the spacing EP01 between the front end face of the lens barrel near the object side and the object side surface of the first spacer element along the optical axis, and the inner diameter d0s of the front end face of the lens barrel near the object side satisfy: 4.63≤(TD×f) / (EP01×d0s)≤6.

70.

5. The optical imaging system according to claim 1, characterized in that, The spacer element further includes a first spacer element disposed between the first lens and the second lens and in contact with the image-side surface of the first lens; wherein, The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the inner diameter d1s of the object side of the first spacer element and the inner diameter d1m of the image side of the first spacer element satisfy: 6.07≤|f1×f2| / (d1s×d1m)≤10.

47.

6. The optical imaging system according to claim 1, characterized in that, At least two of the first to fourth lenses are meniscus lenses in the paraxial region.

7. The optical imaging system according to claim 1, characterized in that, The radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: R2>R1>0.

8. The optical imaging system according to any one of claims 1 to 7, characterized in that, The spacer element further includes a first spacer element disposed between the first lens and the second lens and in contact with the image-side surface of the first lens; wherein, 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 spacing EP12 between the image side of the first spacer element and the object side of the second spacer element along the optical axis, and the maximum thickness CP2 of the second spacer element along the optical axis satisfy: 30.85≤(R3+R4) / (EP12+CP2)≤76.

76.

9. The optical imaging system according to any one of claims 1 to 7, characterized in that, The radius of curvature R5 of the object side of the third lens, the radius of curvature R6 of the image side of the third lens, the inner diameter d2s of the object side of the second spacer element, and the inner diameter d3s of the object side of the third spacer element satisfy: 0 < |R6 / R5|×(d3s / d2s)≤5.

18.

10. The optical imaging system according to any one of claims 1 to 7, characterized in that, The effective focal length f4 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: 2.37≤|f4| / (d3m+D3m)<25.

11. The optical imaging system according to any one of claims 1 to 7, characterized in that, The spacer element further includes a fifth spacer element disposed between the fifth lens and the sixth lens and in contact with the image-side surface of the fifth lens; wherein, The effective focal length f5 of the fifth lens, the maximum thickness CP4 of the fourth spacer element along the optical axis, and the spacing EP45 between the image side of the fourth spacer element and the object side of the fifth spacer element along the optical axis satisfy: 3.11≤f5 / (CP4+EP45)≤7.

26.

12. The optical imaging system according to any one of claims 2 to 7, characterized in that, The plurality of spacers further includes a first spacer element disposed between the first lens and the second lens and in contact with the image-side surface of the first lens, and a fifth spacer element disposed between the fifth lens and the sixth lens and in contact with the image-side surface of the fifth lens, wherein, The effective focal length f1 of the first lens, the effective focal length f6 of the sixth lens, the spacing EP01 between the front end face of the lens barrel near the object side and the object side face of the first spacer element along the optical axis direction, and the maximum thickness CP5 of the fifth spacer element along the optical axis direction satisfy: 1.09≤(f1+f6) / (EP01+CP5)≤2.

21.

13. The optical imaging system according to any one of claims 1 to 7, characterized in that, The spacer element further includes a fifth spacer element disposed between the fifth lens and the sixth lens 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, and the maximum thickness CP5 of the fifth spacer element along the optical axis satisfy: 1.68≤|f5+f6| / CP5≤15.

93.

14. The optical imaging system according to any one of claims 1 to 7, characterized in that, The radius of curvature R8 of the image side of the fourth lens, the radius of curvature R9 of the object side of the fifth lens, the inner diameter d4s of the object side of the fourth spacer element, and the inner diameter d4m of the image side of the fourth spacer element satisfy: 5.76≤(R8×R9) / (d4s×d4m)≤38.

67.

15. The optical imaging system according to any one of claims 1 to 7, characterized in that, The spacer element further includes a fifth spacer element disposed between the fifth lens and the sixth lens and in contact with the image-side surface of the fifth lens; wherein, The inner diameter d5s of the object side of the fifth spacer element, the inner diameter d5m of the image side of the fifth spacer element, the radius of curvature R10 of the image side of the fifth lens, and the radius of curvature R11 of the object side of the sixth lens satisfy: 5.02≤(d5s×d5m) / (R10×R11)≤8.

53.

16. The optical imaging system according to any one of claims 1 to 7, characterized in that, The inner diameter d0m of the rear end face of the lens barrel near the image side, the outer diameter D0m of the rear end face of the lens barrel near the image side, and the radius of curvature R12 of the image side surface of the sixth lens satisfy: 4.18≤(d0m+D0m) / R12≤9.52.

Images