Optical imaging system

Abstract

The application discloses an optical imaging system, which comprises: a lens group sequentially comprising a first lens, a second lens, a third lens and a fourth lens from an object side to an image side along an optical axis; a plurality of spacer elements comprising at least four spacer elements; and a lens barrel for accommodating the lens group and the plurality of spacer elements, wherein the lens barrel comprises an object end surface close to the object side, an image end surface close to the image side, an outer wall and an inner wall; the effective focal length of the first lens is positive and smaller than the effective focal length of other lenses with positive focal length, the curvature radius of the object side surface of the second lens is smaller than zero; and the inner diameter d0m of the image end surface of the lens barrel close to the image side, the outer diameter D0s of the object end surface of the lens barrel close to the object side and the distance TD of the object side surface of the first lens to the image side surface of the fourth lens on the optical axis satisfy 1.0<(d0m-D0s) / TD<2.0.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical elements, in particular to an optical imaging system. BACKGROUND

[0002] With the rapid development of the semiconductor industry, the progress of semiconductor technology promotes the rapid improvement of the performance of electronic photosensitive elements. At the same time, with the gradual popularization of intelligent devices, people have higher and higher requirements for camera lenses, not only high-quality imaging effect, but also aesthetic appearance. At present, under-screen photography technology is widely used, which can increase the screen ratio and improve the appearance. However, the under-screen camera will cause the screen on the front of the device to be incomplete, which still affects the appearance of the device, so the camera lens needs to develop towards the trend of small head. Small head means that the camera lens head diameter is smaller, which makes the screen ratio larger and has less impact on the appearance of the device. While reducing the size of the lens head, it is also necessary to ensure high imaging effect, which brings great challenges to lens manufacturers.

[0003] Therefore, designing an optical imaging system with small size, small head and good imaging quality is one of the key research topics for designers in the field. SUMMARY

[0004] One aspect of the present application provides an optical imaging system, which includes: a lens group including, in order from an object side to an image side along an optical axis, a first lens, a second lens, a third lens, and a fourth lens; a plurality of spacer elements including at least four spacer elements; and a lens barrel for accommodating the lens group and the plurality of spacer elements, wherein the first lens has a positive effective focal length, and the effective focal length of the first lens is smaller than the effective focal length of other lenses having a positive focal length, and the object side surface of the second lens has a negative curvature radius; the lens barrel includes an object end surface close to the object side, an image end surface close to the image side, an outer wall, and an inner wall; the inner diameter d0m of the image end surface close to the image side of the lens barrel, the outer diameter D0s of the object end surface close to the object side of the lens barrel, and the distance TD from the object side surface of the first lens to the image side surface of the fourth lens on the optical axis satisfy: 1.0 < (d0m-D0s) / TD < 2.0.

[0005] In one embodiment, the distance from the effective diameter surface of the object side surface of the first lens to the image end surface close to the image side of the lens barrel in the optical axis direction gradually decreases from the center to the edge of the effective diameter surface of the object side surface of the first lens.

[0006] In one 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, and the curvature radius R3 of the object side surface of the second lens satisfy: R2 / R1 > 0 and R2 / R3 < 0.

[0007] In one embodiment, 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, and the radius of curvature R2 of the image side surface of the first lens satisfy: R5 / R6 > 0 and R5 / R2 < 0.

[0008] In one embodiment, the plurality of spacer elements includes a first spacer element disposed on the image side surface of the first lens and at least partially in contact with the first lens; wherein the first spacer element includes an object side surface proximate to the object side, an image side surface proximate to the image side, an inner diameter surface parallel to the optical axis, and an outer diameter surface parallel to the optical axis.

[0009] In one embodiment, the inner wall of the lens barrel has a first parallel surface proximate to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element is in contact with the first parallel surface of the inner wall of the lens barrel.

[0010] In one embodiment, the inner wall of the lens barrel has a first parallel surface proximate to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element has a spacing from the first parallel surface of the inner wall of the lens barrel in a direction perpendicular to the optical axis.

[0011] In one embodiment, the inner wall of the lens barrel has a first parallel surface proximate to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element has a spacing HP1 from the first parallel surface of the inner wall of the lens barrel in a direction perpendicular to the optical axis, which satisfies: 0 mm < HP1 < 0.5 mm.

[0012] In one embodiment, the plurality of spacer elements includes a first spacer element disposed on the image side surface of the first lens and at least partially in contact with the first lens, and a second spacer element disposed on the image side surface of the second lens and at least partially in contact with the second lens; wherein the air spacing T12 of the first lens and the second lens on the optical axis, the air spacing T23 of the second lens and the third lens on the optical axis, the central thickness CT2 of the second lens on the optical axis, the spacing distance EP01 of the object end surface of the lens barrel proximate to the object side to the object side surface of the first spacer element along the optical axis, and the spacing distance EP12 of the first spacer element and the second spacer element along the optical axis satisfy: 0 < (T12 + CT2 + T23) / (EP01 + EP12) < 1.0.

[0013] In one embodiment, the plurality of spacer elements includes a first spacer element disposed on the image side surface of the first lens and at least partially in contact with the first lens, and a second spacer element disposed on the image side surface of the second lens and at least partially in contact with the second lens; wherein the inner diameter d1s of the object side surface of the first spacer element, the inner diameter d2s of the object side surface of the second spacer element, the radius of curvature R2 of the image side surface of the first lens, and the radius of curvature R3 of the object side surface of the second lens satisfy: |d1s / R2 + d2s / R3| < 1.0.

[0014] In one embodiment, the minimum inner diameter ds of the front end portion of the lens barrel facing the object side and the maximum field of view FOV of the optical imaging system satisfy: ds / tan(FOV / 2) < 1.5 mm.

[0015] In one embodiment, the outer wall of the lens barrel has a first vertical surface perpendicular to the optical axis near the object side; wherein the distance H1 from the object end surface of the lens barrel near the object side to the first vertical surface and the height L of the lens barrel along the optical axis satisfy: H1 / L < 0.5.

[0016] In one embodiment, the plurality of spacer elements includes a first spacer element disposed on the image side surface of the first lens and at least partially in contact with the first lens; wherein the maximum outer diameter D1 of the first lens, the outer diameter D1s of the object side surface of the first spacer element, the central thickness CT1 of the first lens along the optical axis, and the maximum thickness CP1 of the first spacer element along the optical axis satisfy: -1.0 < (D1-D1s) / (CT1+CP1) < 2.0.

[0017] In one embodiment, the maximum thickness of at least one spacer element in the plurality of spacer elements disposed between the image side surface of the third lens and the image end surface of the lens barrel near the image side along the optical axis is greater than 0.1 mm.

[0018] In one embodiment, the plurality of spacer elements includes a second spacer element disposed on the image side surface of the second lens and at least partially in contact with the second lens and a third spacer element disposed on the image side surface of the third lens and at least partially in contact with the third lens; wherein the refractive index N2 of the second lens, the refractive index N3 of the third lens, the outer diameter D2s of the object side surface of the second spacer element, the outer diameter D3s of the object side surface of the third spacer element, and the separation distance EP23 of the second spacer element and the third spacer element along the optical axis satisfy: 1.0 < (N2 / D2s+N3 / D3s) / EP23 < 6.0.

[0019] In one embodiment, the plurality of spacer elements includes a second spacer element disposed on the image side surface of the second lens and at least partially in contact with the second lens and a third spacer element disposed on the image side surface of the third lens and at least partially in contact with the third lens; wherein the Abbe number V2 of the second lens, the Abbe number V3 of the third lens, the maximum thickness CP2 of the second spacer element along the optical axis, and the maximum thickness CP3 of the third spacer element along the optical axis satisfy: 0 < (V2 / CP2) / (V3 / CP3) < 4.0.

[0020] In one embodiment, the plurality of spacer elements includes a third spacer element disposed on the image side of the third lens and in at least partial contact with the third lens; wherein an inner diameter d3sof the object side surface of the third spacer element, a maximum thickness CP3of the third spacer element along the optical axis direction, a radius of curvature R6of the image side surface of the third lens, a radius of curvature R7of the object side surface of the fourth lens, and an air separation T34of the third lens and the fourth lens on the optical axis satisfy: -25.0 < (d3s / CP3) / (R6-R7) x T34< 0.

[0021] Another aspect of the present application also provides an optical imaging system, comprising: a lens group including, in order from the object side to the image side along an optical axis, a first lens, a second lens, a third lens, and a fourth lens; a plurality of spacer elements including at least four spacer elements; and a lens barrel for accommodating the lens group and the plurality of spacer elements; an effective diameter of the object side surface of the first lens gradually decreases from a center to an edge of the effective diameter of the object side surface of the first lens along the optical axis direction; a sign of an effective focal length of the first lens is positive and is smaller than effective focal lengths of other lenses having positive focal lengths, a radius of curvature of the object side surface of the second lens is smaller than zero; and an air separation T12of the first lens and the second lens on the optical axis, an air separation T23of the second lens and the third lens on the optical axis, a central thickness CT2of the second lens on the optical axis, a separation distance EP01from the object end surface of the lens barrel near the object side to the object side surface of the first spacer element along the optical axis direction, and a separation distance EP12of the first spacer element and the second spacer element along the optical axis direction satisfy: 0 < (T12+CT2+T23) / (EP01+EP12)< 1.0.

[0022] In one embodiment, an inner diameter d0mof the image end surface of the lens barrel near the image side, an outer diameter D0sof the object end surface of the lens barrel near the object side, and a distance TDof the object side surface of the first lens to the image side surface of the fourth lens on the optical axis satisfy: 1.0 < (d0m-D0s) / TD< 2.0.

[0023] In one embodiment, a radius of curvature R1of the object side surface of the first lens, a radius of curvature R2of the image side surface of the first lens, and a radius of curvature R3of the object side surface of the second lens satisfy: R2 / R1> 0 and R2 / R3< 0.

[0024] In one embodiment, a radius of curvature R5of the object side surface of the third lens, a radius of curvature R6of the image side surface of the third lens, and a radius of curvature R2of the image side surface of the first lens satisfy: R5 / R6> 0 and R5 / R2< 0.

[0025] In one embodiment, the plurality of spacer elements includes a first spacer element disposed on the image side of the first lens and at least partially in contact with the first lens; wherein the first spacer element includes an object side surface proximate to the object side, an image side surface proximate to the image side, an inner diameter surface parallel to the optical axis, and an outer diameter surface parallel to the optical axis.

[0026] In one embodiment, the inner wall of the lens barrel has a first parallel surface proximate to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element is in contact with the first parallel surface of the inner wall of the lens barrel.

[0027] In one embodiment, the inner wall of the lens barrel has a first parallel surface proximate to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element has a spacing distance HP1 from the first parallel surface of the inner wall of the lens barrel in a direction perpendicular to the optical axis, wherein 0 mm < HP1 < 0.5 mm.

[0028] In one embodiment, the inner wall of the lens barrel has a first parallel surface proximate to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element has a spacing distance HP1 from the first parallel surface of the inner wall of the lens barrel in a direction perpendicular to the optical axis, wherein 0 mm < HP1 < 0.5 mm.

[0029] In one embodiment, the plurality of spacer elements includes a first spacer element disposed on the image side of the first lens and at least partially in contact with the first lens, and a second spacer element disposed on the image side of the second lens and at least partially in contact with the second lens; wherein an inner diameter of the object side surface of the first spacer element d1s, an inner diameter of the object side surface of the second spacer element d2s, a radius of curvature of the image side surface of the first lens R2, and a radius of curvature of the object side surface of the second lens R3 satisfy: |d1s / R2 + d2s / R3| < 1.0.

[0030] In one embodiment, a minimum inner diameter ds of a front end portion of the lens barrel facing the object side and a maximum field of view FOV of the optical imaging system satisfy: ds / tan(FOV / 2) < 1.5 mm.

[0031] In one embodiment, the outer wall of the lens barrel has a first perpendicular surface proximate to the object side and perpendicular to the optical axis; wherein a distance H1 from the object end surface of the lens barrel proximate to the object side to the first perpendicular surface and a height L of the lens barrel along the optical axis satisfy: H1 / L < 0.5. In one embodiment, the plurality of spacer elements includes a first spacer element disposed on the image side of the first lens and at least partially in contact with the first lens; wherein a maximum outer diameter of the first lens D1, an outer diameter of the object side surface of the first spacer element D1s, a central thickness of the first lens along the optical axis CT1, and a maximum thickness of the first spacer element along the optical axis CP1 satisfy: -1.0 < (D1-D1s) / (CT1+CP1) < 2.0.

[0032] In one embodiment, the maximum thickness of at least one of the plurality of spacer elements placed between the image-side surface of the third lens and the image end surface of the lens barrel close to the image side in the direction of the optical axis is greater than 0.1 mm.

[0033] In one embodiment, the plurality of spacer elements includes a second spacer element placed on the image-side surface of the second lens and at least partially in contact with the second lens, and a third spacer element placed on the image-side surface of the third lens and at least partially in contact with the third lens; wherein the refractive index N2 of the second lens, the refractive index N3 of the third lens, the outer diameter D2s of the object-side surface of the second spacer element, the outer diameter D3s of the object-side surface of the third spacer element, and the interval distance EP23 of the second spacer element and the third spacer element in the direction of the optical axis satisfy: 1.0 < (N2 / D2s+N3 / D3s) / EP23 < 6.0.

[0034] In one embodiment, the plurality of spacer elements includes a second spacer element placed on the image-side surface of the second lens and at least partially in contact with the second lens, and a third spacer element placed on the image-side surface of the third lens and at least partially in contact with the third lens; wherein the refractive index N2 of the second lens, the refractive index N3 of the third lens, the outer diameter D2s of the object-side surface of the second spacer element, the outer diameter D3s of the object-side surface of the third spacer element, and the interval distance EP23 of the second spacer element and the third spacer element in the direction of the optical axis satisfy: 1.0 < (N2 / D2s+N3 / D3s) / EP23 < 6.0.

[0035] In one embodiment, the plurality of spacer elements includes a third spacer element placed on the image-side surface of the third lens and at least partially in contact with the third lens; wherein the inner diameter d3s of the object-side surface of the third spacer element, the maximum thickness CP3 of the third spacer element in the direction of the optical axis, the curvature radius R6 of the image-side surface of the third lens, the curvature radius R7 of the object-side surface of the fourth lens, and the air interval T34 of the third lens and the fourth lens on the optical axis satisfy: -25.0 < (d3s / CP3) / (R6-R7) x T34 < 0.

[0036] The optical imaging system provided in the present application includes a plurality of lenses, a plurality of spacer elements, and a lens barrel. By controlling the focal length of the first lens and the curvature of the object-side surface of the second lens, the convergence of the light rays of each field of view of the optical imaging system is facilitated, the aberration generated by the front end optics of the optical imaging system is reduced, and at the same time, the size of the front end of the lens is also reduced. In the case where the height of the lens in the direction of the optical axis is determined, the on-axis distance from the object-side surface of the first lens to the image-side surface of the last lens and the size of the end surface of the lens are controlled, the design of the small head is realized, the assembly stability and the coaxiality of the lenses are ensured, the screen ratio of the lens is smaller, the lens has less influence on the appearance of the loading device, the lens on the loading device is less visible, and the loading device is more beautiful under the condition of ensuring the optical performance of the lens. BRIEF DESCRIPTION OF DRAWINGS

[0037] Other features, objects, and advantages of the application will become more apparent from the following detailed description when read in conjunction with the accompanying drawings:

[0038] FIG. 1 A structural arrangement diagram and a schematic diagram of partial parameters of an optical imaging system according to the present application are shown;

[0039] FIG. 2A to FIG. 2C A structural schematic diagram of an optical imaging system according to Embodiment 1 of the present application is shown;

[0040] FIG. 3A to FIG. 3D An on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system according to Embodiment 1 of the present application are respectively shown;

[0041] FIG. 4A to FIG. 4C A structural schematic diagram of an optical imaging system according to Embodiment 2 of the present application is shown;

[0042] FIG. 5A to FIG. 5D An on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system according to Embodiment 2 of the present application are respectively shown;

[0043] FIG. 6A to FIG. 6C A structural schematic diagram of an optical imaging system according to Embodiment 3 of the present application is shown; and

[0044] FIG. 7A to FIG. 7D An on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system according to Embodiment 3 of the present application are shown. DETAILED DESCRIPTION

[0045] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that the detailed description is only a description of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Throughout the specification, like reference numerals refer to like elements. The expression “and / or” includes any and all combinations of one or more of the associated listed items.

[0046] It should be noted that, in the present specification, the expressions first, second, third, and the like are merely used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0047] In the drawings, the thickness, size, and shape of the lenses have been exaggerated slightly for ease of explanation. Specifically, the shape of the spherical or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0048] In this document, the curvature or the paraxial curvature refers to the curvature of a region near the optical axis. If the curvature of a lens surface is positive and the position of the curvature is not specified, 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 the position of the curvature is not specified, it means that the curvature of the lens surface is negative at least in the paraxial region. The surface of each lens close to the object is referred to as the object side surface of the lens, and the surface of each lens close to the imaging surface is referred to as the image side surface of the lens.

[0049] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. Furthermore, as used herein, expressions such as "at least one of" a list of items shall be understood as meaning one or more items of the list and only those one or more items.

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0051] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The following embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but should not be understood as a limitation on the scope of the patent of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. For example, the lens group (i.e. the first lens to the fourth lens), the lens barrel, and the spacer element in each embodiment of the present application can be combined arbitrarily, and are not limited to the combination of the lens group, the lens barrel, the spacer element, etc. in the embodiment.

[0052] The present application will be described in detail below with reference to the accompanying drawings and embodiments. In which, FIG. 1 A structural arrangement diagram and a schematic diagram of some parameters of an optical imaging system according to the present application are shown. It should be understood by those skilled in the art that some parameters of lenses often used in the art, such as the central thickness CT3 of the third lens on the optical axis, are not shown in the drawings, FIG. 1 , FIG. 1 Some parameters of the lens barrel and the spacer element of an optical imaging system according to the present application are shown only exemplarily in order to better understand the present application, as shown in FIG. 1 ,

[0053] EP01 represents the interval distance of the optical axis direction from the object end surface of the lens barrel close to the object side to the object side surface of the first spacer element;

[0054] EP12 represents the interval distance of the optical axis direction between the first spacer element and the second spacer element;

[0055] EP23 represents the interval distance of the optical axis direction between the second spacer element and the third spacer element;

[0056] CP2 represents the maximum thickness of the second spacer element in the direction of the optical axis;

[0057] CP3 represents the maximum thickness of the third spacer element in the direction of the optical axis;

[0058] H1 represents the distance from the object end surface of the lens barrel close to the object side to its first perpendicular surface;

[0059] L represents the height of the lens barrel in the direction of the optical axis (i.e. the distance in the direction of the optical axis from the object end surface of the lens barrel close to the object side to the image end surface of the lens barrel close to the image side);

[0060] ds represents the minimum inner diameter of the front end portion of the lens barrel facing the object side;

[0061] D0s represents the outer diameter of the object end surface of the lens barrel close to the object side;

[0062] d2s represents the inner diameter of the object side surface of the second spacer element;

[0063] D1 represents the maximum outer diameter of the first lens;

[0064] D1s represents the outer diameter of the object side surface of the first spacer element;

[0065] D3s represents the outer diameter of the object side surface of the third spacer element;

[0066] d3s represents the inner diameter of the object side surface of the third spacer element; and

[0067] d0m represents the inner diameter of the image end surface of the lens barrel close to the image side.

[0068] The features, principles, and other aspects of the present application are described in detail below.

[0069] In an example embodiment, an optical imaging system according to the example embodiments of the present application includes a lens barrel, and a plurality of spacer elements and a lens group disposed in the lens barrel. The lens group includes, in order from an object side to an image side along an optical axis, a first lens, a second lens, a third lens, and a fourth lens. The plurality of spacer elements includes at least four spacer elements.

[0070] In an example embodiment, the first lens has positive refractive power, a curvature radius of the object side surface thereof is positive, and a curvature radius of the image side surface thereof is positive. By controlling the refractive power and the surface shape of the first lens, the convergence of the light rays of each field of view of the optical imaging system is facilitated, and the contribution of the first lens to the spherical aberration of the system is reduced.

[0071] In an example embodiment, the distance from the effective diameter surface of the object side surface of the first lens to the image end surface of the lens barrel near the image side is gradually reduced from the center to the edge of the effective diameter surface of the object side surface of the first lens. By reasonably controlling the surface shape of the first lens, the contribution of the first lens to the low-order aberration of the system is reduced.

[0072] In an example embodiment, the second lens has positive refractive power or negative refractive power, and a curvature radius of the object side surface thereof is negative. By reasonably configuring the refractive power and the curvature of the object side surface of the second lens, the spherical aberration of the first lens is compensated.

[0073] In an example embodiment, the third lens has positive refractive power or negative refractive power, a curvature radius of the object side surface thereof is negative, and a curvature radius of the image side surface thereof is negative. By reasonably configuring the shape of the third lens, the amount of astigmatism generated by the front-end optics and the rear-end optics of the optical imaging system is balanced, so that the optical imaging system has good imaging quality.

[0074] In an example embodiment, the fourth lens has positive refractive power or negative refractive power, a curvature radius of the object side surface thereof is positive, and a curvature radius of the image side surface thereof is positive. By controlling the refractive power and the curvature of the fourth lens, the aberration of the front-end optics of the optical imaging system is compensated, so that the optical imaging system has good imaging quality.

[0075] In the example embodiment, the lens barrel has an object end surface close to the object side, an image end surface close to the image side, an outer wall, and an inner wall, wherein the outer wall surface of the lens barrel has at least one surface perpendicular to the optical axis. The object end surface of the lens barrel meets the appearance requirement, ensuring the lens appearance, the image end surface of the lens barrel is used to determine the distance between the lens group and the imaging chip, ensuring the optical performance of the lens, the outer wall of the lens barrel cooperates with the module to realize the installation and fixation of the whole lens, the inner wall of the lens barrel cooperates with the lens outer diameter to ensure the stability of the lens group, and the part of the outer wall surface of the lens barrel perpendicular to the optical axis is used for lens positioning and fixation, facilitating the lens group assembly and ensuring the lens coaxiality.

[0076] In the example embodiment, the plurality of spacer elements includes at least four spacer elements, which ensure the stability of the lens group assembly, effectively ensure the thickness of the air gap in the lens, make the optical parameters of the lens meet the design requirements, prevent the interference between the lenses and the lens effective diameter surface in the optical axis direction after assembly, effectively intercept stray light, avoid lens appearance problems and performance abnormalities, and improve the appearance and performance yield.

[0077] In the example embodiment, the plurality of spacer elements includes a first spacer element, a second spacer element, a third spacer element, and a plurality of auxiliary spacer elements, wherein the first spacer element is arranged on the image side of the first lens and at least partially contacts the first lens; the second spacer element is arranged on the image side of the second lens and at least partially contacts the second lens; and the third spacer element is arranged on the image side of the third lens and at least partially contacts the third lens.

[0078] In the example embodiment, the first spacer element includes an object side surface close to the object side, an image side surface close to the image side, an inner diameter surface parallel to the optical axis, and an outer diameter surface parallel to the optical axis. The first spacer element can effectively intercept stray light, meet the demand for improving stray light, and the thickness of the first spacer element can adjust the optical field curvature, improve the imaging quality and performance yield of the optical imaging system. Meanwhile, the object side surface of the first spacer element contacts the image side surface of the first lens, the contact surface is perpendicular to the optical axis direction, ensures the accuracy of the installation of the optical imaging system, and the larger the contact area of the two, the better the assembly stability of the optical imaging system.

[0079] In the example embodiment, the inner wall of the lens barrel has a first parallel surface close to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element contacts the first parallel surface of the lens barrel. When the first lens and the second lens are assembled in a stacking form, the outer diameter of the first spacer element is consistent with the inner diameter of the first parallel surface of the lens barrel, which can ensure the accurate installation of the first spacer element, is conducive to ensuring the assembly needs of the optical imaging system, and ensures that the position of the first spacer element does not deviate after installation, which will not block the normal light path of the optical system.

[0080] In the example embodiment, the outer diameter surface of the first spacing element and the first parallel surface of the inner wall of the lens barrel have a spacing in the direction perpendicular to the optical axis. When the snap-fit structure is provided between the first lens and the second lens, the cooperation of the two lenses is more accurate, which is beneficial to improve the optical performance of the lens. At this time, the spacing between the outer diameter surface of the first spacing element and the first parallel surface of the inner wall of the lens barrel is mainly determined by the thickness of the outer convex edge of the first lens, and the first spacing element mainly plays a role of blocking stray light, and has little effect on the assembly of the lens.

[0081] In the example embodiment, the spacing distance HP1 between the outer diameter surface of the first spacing element and the first parallel surface of the inner wall of the lens barrel in the direction perpendicular to the optical axis satisfies: 0mm≤HP1<0.5mm. Different distances HP1 are provided for the first lens and the second lens in the form of stacking or the snap-fit structure. For example, when the first lens and the second lens are in the form of stacking, HP1=0mm, which can ensure the accurate installation of the first spacing element, is beneficial to ensure the assembly requirement of the optical imaging system, and ensures that the position of the first spacing element does not deviate after installation and does not block the normal light path of the optical imaging system. For example, when the snap-fit structure is provided between the first lens and the second lens, 0mm<HP1<0.5mm, and HP1 is mainly determined by the thickness of the outer convex edge of the first lens. At this time, the first spacing element mainly plays a role of blocking stray light, and has little effect on the assembly of the lens.

[0082] In the example embodiment, the plurality of auxiliary spacing elements can include at least one of a first auxiliary spacing element disposed on the image side of the first spacing element and at least partially in contact with the first spacing element, a second auxiliary spacing element disposed on the image side of the second spacing element and at least partially in contact with the second spacing element, and a third auxiliary spacing element disposed on the image side of the third spacing element and at least partially in contact with the third spacing element. The auxiliary spacing element is beneficial to meet the requirement of structural rationality. For example, the object side of the third auxiliary spacing element is in contact with the image side of the third spacing element, and the object side of the third spacing element is in contact with the image side of the third lens. The larger the overlapping area of the two contact regions in the direction perpendicular to the optical axis, the more stable the structure assembly. In addition, the outer diameter of the third auxiliary spacing element cooperates with the inside of the lens barrel to ensure the coaxiality of the spacing element.

[0083] In the example embodiment, the plurality of auxiliary spacing elements can further include a fourth auxiliary spacing element disposed on the image side of the third auxiliary spacing element and at least partially in contact with the third auxiliary spacing element. The auxiliary spacing element is beneficial to meet the requirement of structural rationality. For example, the object side of the fourth auxiliary spacing element is in contact with the image side of the third auxiliary spacing element, and the image side of the fourth auxiliary spacing element is in contact with the object side of the fourth lens. The larger the overlapping area of the two contact regions in the direction perpendicular to the optical axis, the more stable the structure assembly.

[0084] In the example embodiment, the optical imaging system according to the present application can satisfy: 1.0 < (d0m-D0s) / TD < 2.0, where d0m is the inner diameter of the image end surface of the lens barrel close to the image side, D0s is the outer diameter of the object end surface of the lens barrel close to the object side, and TD is the distance on the optical axis from the object side surface of the first lens to the image side surface of the fourth lens. More specifically, d0m, D0s and TD can further satisfy: 1.1 < (d0m-D0s) / TD < 1.7. Satisfying 1.0 < (d0m-D0s) / TD < 2.0 can ensure the rationality of the overall structure of the small head lens. In the case of determining the height of the lens along the optical axis, controlling the axial distance from the object side surface of the first lens to the image side surface of the last lens and the head diameter of the lens (i.e., the outer diameter of the object end surface of the lens barrel close to the object side) is conducive to a smaller screen ratio of the lens, which makes the lens have less impact on the appearance of the loading device, and under the condition of ensuring the optical performance of the lens, the lens on the loading device is less visible and more beautiful.

[0085] In the example embodiment, 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 and the radius of curvature R3 of the object side surface of the second lens satisfy: R2 / R1 > 0 and R2 / R3 < 0, which controls the curvatures of the first lens and the second lens, and is conducive to reducing the contribution amount of spherical aberration to the system.

[0086] In the example embodiment, 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 and the radius of curvature R2 of the image side surface of the first lens satisfy: R5 / R6 > 0 and R5 / R2 < 0, which controls the curvatures of the first lens and the third lens, and is conducive to balancing the amount of astigmatism generated by the front-end optics and the rear-end optics of the optical imaging system, so that the optical imaging system has good imaging quality.

[0087] In exemplary embodiments, the fourth lens has positive refractive power, and a radius of curvature R7 of an object side surface of the fourth lens and a radius of curvature R8 of an image side surface of the fourth lens satisfy: R7 / R8>0. By controlling the refractive power and the radius of curvature of the fourth lens, the degree of bending of the fourth lens surface can be controlled, and the balance between the front optical and the rear optical of the optical imaging lens can be achieved. In exemplary embodiments, the optical imaging system according to the present application can satisfy: 0<(T12+CT2+T23) / (EP01+EP12)<1.0, where T12 is the air gap of the first lens and the second lens on the optical axis, T23 is the air gap of the second lens and the third lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, EP01 is the interval distance from the object end surface of the barrel close to the object side to the object side surface of the first spacer element along the optical axis, and EP12 is the interval distance between the first spacer element and the second spacer element along the optical axis. More specifically, T12, CT2, T23, EP01 and EP12 can further satisfy: 0.6<(T12+CT2+T23) / (EP01+EP12)<0.9. Satisfying 0<(T12+CT2+T23) / (EP01+EP12)<1.0 can help to meet the structural control requirements, make the lens head structure distribution more reasonable, improve the assembly stability, and reasonably control the edge thickness of the second lens and the center thickness of the second lens on the optical axis, so as to ensure that the lens has good processing feasibility. In addition, reasonably controlling the air gap on both sides of the second lens and the thickness of the second lens can prevent the lens and the effective diameter surface of the lens from interfering with each other on the optical axis after assembly, avoid performance abnormalities, and improve the performance yield.

[0088] In exemplary embodiments, the optical imaging system according to the present application can satisfy: |d1s / R2+d2s / R3|<1.0, where d1s is the inner diameter of the object side surface of the first spacer element, d2s is the inner diameter of the object side surface of the second spacer element, R2 is the radius of curvature of the image side surface of the first lens, and R3 is the radius of curvature of the object side surface of the second lens. More specifically, d1s, R2, d2s and R3 can further satisfy: |d1s / R2+d2s / R3|<0.26. Satisfying |d1s / R2+d2s / R3|<1.0 can help to ensure the performance and imaging quality of the optical imaging system. Specifically, the distribution of the radius of curvature R2 of the image side surface of the first lens and the radius of curvature R3 of the object side surface of the second lens determines the concave-convex degree of the image side surface of the second lens and the object side surface of the third lens, affects the exiting state of the light from the second lens and the entering state of the light into the third lens, and further affects the imaging effect of the lens. The inner diameter d1s of the object side surface of the first spacer element determines the blocking degree of the first spacer element to the light path of the second lens. The inner diameter d2s of the object side surface of the second spacer element determines the blocking degree of the second spacer element to the light path of the third lens, and further affects the imaging quality of the lens.

[0089] In the example embodiments, the optical imaging system according to the present application can satisfy: ds / tan(FOV / 2) < 1.5 mm, where ds is the minimum inner diameter of the front end portion of the lens barrel facing the object side, and FOV is the maximum field of view angle of the optical imaging system. More specifically, ds and FOV can further satisfy: ds / tan(FOV / 2) < 1.3 mm. Satisfying ds / tan(FOV / 2) < 1.5 mm is conducive to ensuring that the optical imaging system satisfies normal shooting requirements, i.e., the minimum inner diameter ds of the front end portion of the lens barrel facing the object to be shot is greater than the diameter of the profile circle corresponding to the position FOV, and the lens barrel design cannot have light blocking and needs to satisfy assembly requirements; satisfying ds / tan(FOV / 2) < 1.5 mm is also conducive to ensuring that the width of the annular plane of the object end surface of the lens barrel close to the object side is not too small, which can ensure normal shooting and satisfy normal assembly requirements.

[0090] In the example embodiments, the outer wall of the lens barrel has a first vertical surface close to the object side and perpendicular to the optical axis; and the optical imaging system according to the present application can satisfy: H1 / L < 0.5, where H1 is the distance from the object end surface of the lens barrel close to the object side to the first vertical surface, and L is the height of the lens barrel along the optical axis (i.e., the distance from the object end surface to the image end surface of the lens barrel along the optical axis). More specifically, H1 and L can further satisfy: H1 / L < 0.25. Satisfying H1 / L < 0.5 is conducive to ensuring the appearance and molding requirements of the lens barrel. The H1 and the total height L of the lens jointly determine the appearance style of the lens, and under the condition of satisfying the motor adaptation, the larger the H1 / L, the smaller the lens appearance adjustment space and the lens layout space, which may result in that the wall thickness of the front half of the lens barrel is too thin, which is not conducive to the molding of the lens barrel.

[0091] In the example embodiments, the optical imaging system according to the present application can satisfy: -1.0 < (D1-D1s) / (CT1+CP1) < 2.0, where D1 is the maximum outer diameter of the first lens, D1s is the outer diameter of the object side surface of the first spacer element, CT1 is the central thickness of the first lens on the optical axis, and CP1 is the maximum thickness of the first spacer element along the optical axis. More specifically, D1, D1s, CT1 and CP1 can further satisfy: -0.7 < (D1-D1s) / (CT1+CP1) < 1.6. Satisfying -1.0 < (D1-D1s) / (CT1+CP1) < 2.0 reasonably arranges the positions of the first lens and the first spacer element, and selects appropriate outer diameter and thickness dimensions, which can improve the assembly stability of the lens. In addition, by controlling the outer diameter of the first lens, the ratio of the outer diameter of the first lens to the central thickness of the first lens on the optical axis can be effectively controlled, and the uniformity of the wall thickness of the head of the lens barrel is ensured, which is conducive to reducing the risk of abnormal appearance of the head of the lens barrel caused by local non-uniform wall thickness during injection molding.

[0092] In the example embodiment, the maximum thickness of at least one spacing element in the plurality of spacing elements, which is disposed between the image side surface of the third lens and the image end surface of the lens barrel close to the image side, along the optical axis direction is greater than 0.1 mm. The chief ray is relatively flat when passing through the first two lenses, and the light path gradually becomes steep when passing through the third lens and the fourth lens. Therefore, the spacing between the image side surface of the third lens and the object side surface of the fourth lens is relatively large. The use of multiple spacing elements and the selection of spacing elements with a large thickness can improve the assembly stability and reliability of the lens and improve the imaging quality of the lens while effectively controlling the optical parameters to meet the design requirements.

[0093] In the example embodiment, the optical imaging system according to the present application can satisfy 1.0 < (N2 / D2s+N3 / D3s) / EP23 < 6.0, where N2 is the refractive index of the second lens, N3 is the refractive index of the third lens, D2s is the outer diameter of the object side surface of the second spacing element, D3s is the outer diameter of the object side surface of the third spacing element, and EP23 is the spacing distance between the second spacing element and the third spacing element along the optical axis direction. More specifically, N2, D2s, N3, D3s, and EP23 can further satisfy 2.6 < (N2 / D2s+N3 / D3s) / EP23 < 4.5. The lens has a small head structure, and the chief ray is relatively flat when entering the lens through the first lens. The outer diameter of the light path region entering the second lens is small, satisfying 1.0 < (N2 / D2s+N3 / D3s) / EP23 < 6.0. The refractive index of the second lens and the third lens, the spacing therebetween, and the thickness of the third lens can be effectively controlled, so that the light path becomes steep when the light passes through the second lens and enters the third lens, the outer diameter of the light path region passing through the third lens is expanded, and a larger image surface is obtained.

[0094] In the example embodiment, the optical imaging system according to the present application can satisfy 0 < (V2 / CP2) / (V3 / CP3) < 4.0, where V2 is the dispersion coefficient of the second lens, V3 is the dispersion coefficient of the third lens, CP2 is the maximum thickness of the second spacing element along the optical axis direction, and CP3 is the maximum thickness of the third spacing element along the optical axis direction. More specifically, V2, CP2, V3, and CP3 can further satisfy 0.4 < (V2 / CP2) / (V3 / CP3) < 3.0. Satisfying 0 < (V2 / CP2) / (V3 / CP3) < 4.0 is conducive to controlling the dispersion coefficients of the second lens and the third lens, effectively controlling the degree of deflection of the light passing through the second lens and the third lens, and improving the imaging quality of the lens. At the same time, by controlling the thickness of the second spacing element and the third spacing element and adjusting the edge thickness of the third lens, the molding of the third lens is ensured, the internal reflection of the lens is reduced, and the need for improving the stray light of the lens is met.

[0095] In the example embodiment, the optical imaging system according to the present application can satisfy: -25.0 < (d3s / CP3) / (R6-R7) x T34 < 0, where d3s is the inner diameter of the object side surface of the third spacer element, CP3 is the maximum thickness of the third spacer element along the optical axis, R6 is the curvature radius of the image side surface of the third lens, R7 is the curvature radius of the object side surface of the fourth lens, and T34 is the air gap of the third lens and the fourth lens on the optical axis. More specifically, d3s, CP3, R6, R7 and T34 can further satisfy: -21.2 < (d3s / CP3) / (R6-R7) x T34 < -0.2. Satisfying -25.0 < (d3s / CP3) / (R6-R7) x T34 < 0, by adjusting the ratio of the inner diameter and the thickness of the third spacer element, the thickness of the third spacer element and the third lens is controlled, which is beneficial to improve the processing feasibility and assembly stability of the lens. The light path between the third lens and the fourth lens is steep, and adjusting the curvature radius of the image side surface of the third lens and the object side surface of the fourth lens and the air gap of the two on the optical axis can make the effective light path all enter the fourth lens, satisfying the design requirements of the optical parameters.

[0096] In the example embodiment, the plurality of spacer elements include a first spacer element disposed on the image side surface of the first lens and at least partially in contact with the first lens, the first lens and the second lens are separated by the first spacer element without contact, and the first lens, the first spacer element and the second lens are connected by stacking. Connecting the first lens and the second lens in a stacking manner can improve the reliability of the lens, which is beneficial to the lens to withstand low-temperature storage, high-temperature and high-humidity tests and drop tests; under the interference of external extreme conditions, the performance change difference of the lens is small, which can make the lens meet more extensive use conditions and make the application scenarios of the ultra-thin lens more abundant.

[0097] In the example embodiment, the plurality of spacer elements include a first spacer element disposed on the image side surface of the first lens and at least partially in contact with the first lens, the first lens and the second lens have a partial contact surface with a certain inclination angle to the optical axis, the first lens and the second lens are connected by clamping, and the first spacer element is disposed on the side of the partial contact surface close to the optical axis. Connecting the first lens and the second lens in a clamping manner can improve the optical performance of the lens, and connecting the first lens and the second lens in a clamping manner makes the relative position of the two more accurate, ensuring the concentricity and coaxiality between the two, satisfying the design requirements of the optical parameters and improving the imaging quality of the lens. In addition, the clamping structure is more stable, which is beneficial to improve the assembly stability.

[0098] In the example embodiment, the plurality of spacer elements of the optical imaging system further comprises a fixed element disposed on the image side of the fourth lens, the fixed element comprising an outer diameter surface parallel to the optical axis, an object side surface close to the object side, and an image side surface close to the image side, the object side surface of the fixed element at least partially contacts the edge of the image side of the fourth lens, and the outer diameter surface of the fixed element at least partially contacts the inner wall of the lens barrel. The image side surface of the fixed element and the gap with the inner wall of the lens barrel are filled with glue, the structure of which makes the load borne by the glue all or most of the shear load, and secondly the tensile load, while increasing the bonding area and improving the load bearing capacity of the glue. The fixed element makes the lens group structure more stable, increases the push-off force of the lens, makes the risk of lens falling failure lower, and ensures the quality of the lens.

[0099] In the example embodiment, the effective focal length f of the optical imaging system can be, for example, in the range of 2.3mm to 2.7mm, the effective focal length f1 of the first lens can be, for example, in the range of 2.6mm to 3.0mm, the effective focal length f2 of the second lens can be, for example, in the range of -8.3mm to 6.8mm, the effective focal length f3 of the third lens can be, for example, in the range of -2.8mm to 50.0mm, and the effective focal length f4 of the fourth lens can be, for example, in the range of -4.7mm to 7.9mm. The optical imaging system according to the present application can have a smaller total optical length in the case of having a large image surface, for example, the total optical length TTL of the optical imaging system can satisfy 2.9mm < TTL < 3.3mm.

[0100] In the example embodiment, the total optical length TTL of the optical imaging system and the effective focal length f of the optical imaging system satisfy: 1.2 < TTL / f < 1.3, which reasonably controls the ratio of TTL and f of the optical imaging system, and is beneficial to maintaining the miniaturization feature of the optical imaging system.

[0101] In the embodiment of the present application, at least one of the lens surfaces of each lens is a non-spherical lens surface, that is, at least one of the object side surface of the first lens to the image side surface of the fourth lens is a non-spherical lens surface. The characteristic of the non-spherical lens is that the curvature is continuously changed from the center of the lens to the periphery of the lens. Unlike the spherical lens which has a constant curvature from the center of the lens to the periphery of the lens, the non-spherical lens has better curvature radius characteristics, and has the advantages of improving the distortion aberration and improving the astigmatism aberration. After adopting the non-spherical lens, the aberration that occurs during imaging can be eliminated as much as possible, thereby improving the imaging quality. Alternatively, the object side surface and the image side surface of all the lenses from the first lens to the fourth lens are non-spherical lens surfaces.

[0102] In the example embodiment, the optical imaging system described above can further comprise a filter for correcting color deviation and / or a protective glass for protecting the photosensitive elements located on the imaging surface.

[0103] The optical imaging system according to the above embodiments of the present application can employ multiple lenses, for example, four lenses as described above. By properly allocating the optical power, surface shape of each lens, and arrangement of each spacer element, etc., the span of each gear of the lens and the barrel is relatively uniform, which enhances the ability of light convergence and improves the imaging quality of the ultra-thin, large image surface imaging lens.

[0104] However, those skilled in the art should understand that the number of lenses constituting the optical imaging system can be changed without departing from the technical solutions claimed by the present application, to obtain the various results and advantages described in the present specification. For example, although four lenses are described in the embodiments, the optical imaging system is not limited to including four lenses. If necessary, the optical imaging system can also include other numbers of lenses.

[0105] The specific embodiments of the optical imaging system applicable to the above embodiments are further described below with reference to the accompanying drawings.

[0106] Embodiment 1

[0107] The following refers to FIG. 2A to FIG. 3D The optical imaging system 1001, the optical imaging system 1002, and the optical imaging system 1003 according to Embodiment 1 of the present application are described. FIG. 2A to FIG. 2C The structural schematic diagrams of the optical imaging system 1001, the optical imaging system 1002, and the optical imaging system 1003 according to Embodiment 1 of the present application are respectively shown.

[0108] As FIG. 2A to FIG. 2C shown, the optical imaging system 1001, the optical imaging system 1002, and the optical imaging system 1003 each include a barrel P0, a lens group E1-E4, and a plurality of spacer elements P1-P3c.

[0109] As FIG. 2A to FIG. 2C shown, the optical imaging system 1001, the optical imaging system 1002, and the optical imaging system 1003 employ the same lens group, which includes, in order from the object side to the image side, a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4. Among them, the first lens E1 has positive optical power, the second lens E2 has negative optical power, the third lens E3 has positive optical power, and the fourth lens E4 has negative optical power. The filter (not shown) has an object side surface S9 (not shown) and an image side surface S10 (not shown). Light from the object passes through each surface S1-S10 in order and is finally imaged on the imaging surface (not shown).

[0110] Table 1 shows a basic parameter table of the lens groups of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Example 1, wherein the units of the radius of curvature, the thickness and the effective focal length are all millimeters (mm).

[0111]

[0112] Table 1

[0113] In the present example, the effective focal length f of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 is 2.39 mm, and the maximum field of view angle FOV of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 is 86.0°.

[0114] In Example 1, the object side and the image side of any one of the first lens E1 to the fourth lens E4 are aspherical surfaces, and the surface type x of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0115]

[0116] wherein x is the sag of the aspherical surface at a position along the optical axis direction at a height of h, c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the inverse of the radius of curvature R in Table 1 above), k is the conic coefficient, and Ai is the correction coefficient of the i-th order of the aspherical surface. Table 2-1 and Table 2-2 give the high-order coefficients A4, A6, A8, A10 and A12 of the aspherical surfaces S1-S8 that can be used in Example 1. 10 12 14 16 18 20 22 24 26 28 30 .

[0117] Face No. A4 A6 A8 A10 A12 A14 A16 S1 3.9228E-03 6.7308E-04 -2.1966E-04 -2.0707E-05 -7.5686E-05 -1.4277E-07 -1.9226E-05 S2 1.8415E-02 -4.8323E-03 -3.3468E-04 -2.5036E-04 -2.4214E-05 -1.7631E-05 -2.5150E-06 S3 -7.7190E-02 -5.5385E-03 -7.6151E-04 1.2752E-04 -6.9043E-05 1.9554E-05 -1.9221E-05 S4 -8.5217E-02 4.4868E-03 -8.5476E-06 2.2614E-03 8.2913E-05 3.4145E-04 -6.2420E-05 S5 -1.3196E-03 1.8090E-02 -8.6317E-03 3.6000E-03 -4.8421E-05 2.5422E-04 -2.2430E-04 S6 7.6476E-02 6.4227E-02 -2.3359E-02 -2.2340E-03 3.0478E-03 1.2222E-03 -7.4348E-04 S7 -2.1665E+00 7.1300E-01 -2.6782E-01 8.9436E-02 -2.6266E-02 7.6358E-03 -3.8866E-03 S8 -3.8319E+00 8.4172E-01 -2.4844E-01 9.8714E-02 -5.0148E-02 1.8328E-02 -9.3654E-03

[0118] Table 2-1

[0119] Face No. A18 A20 A22 A24 A26 A28 A30 S1 -3.6497E-07 -9.6719E-06 -2.0891E-06 -2.0427E-06 2.6812E-06 1.4476E-07 -1.7000E-07 S2 -1.0894E-06 2.8143E-07 8.7639E-07 -5.0682E-07 -8.0301E-07 8.4747E-07 -1.3343E-07 S3 3.8461E-06 -5.4682E-06 1.8672E-06 4.4237E-06 1.8836E-06 2.2506E-07 -6.1562E-07 S4 5.2227E-05 -2.8039E-05 4.7709E-06 -1.3442E-05 1.3244E-06 -3.5811E-06 1.8166E-06 S5 2.5161E-05 -4.5597E-05 1.7562E-05 2.2045E-06 -2.5425E-06 -4.1182E-06 2.1387E-06 S6 -1.4320E-04 1.8072E-04 6.3218E-05 -3.4697E-05 -2.8944E-06 5.3379E-06 -4.5618E-06 S7 1.8127E-03 -1.0171E-03 3.3375E-04 -5.7991E-05 -1.4105E-05 -1.5937E-05 3.6039E-05 S8 4.9770E-03 -2.9386E-03 5.3192E-04 -8.8716E-04 3.2130E-04 4.5040E-05 1.3385E-04

[0120] Table 2-2

[0121] As FIG. 2A to FIG. 2C ​​​​​​​​​​As shown, the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 each include five spacer elements, which are the first spacer element P1, the second spacer element P2, the third spacer element P3, the third auxiliary spacer element P3b and the fourth auxiliary spacer element P3c, respectively. The first spacer element P1 is disposed on the image side of the first lens E1 and at least partially contacts the first lens E1; the second spacer element P2 is disposed on the image side of the second lens E2 and at least partially contacts the second lens E2; the third spacer element P3 is disposed on the image side of the third lens E3 and at least partially contacts the third lens E3; the third auxiliary spacer element P3b is disposed on the image side of the third spacer element P3 and at least partially contacts the third spacer element P3; and the fourth auxiliary spacer element P3c is disposed on the image side of the third auxiliary spacer element P3b and at least partially contacts the third auxiliary spacer element P3b.

[0122] As shown in FIG. 1, the optical imaging system 1001 includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4 and a fifth lens E5, which are sequentially arranged along the optical axis O. FIG. 2A to FIG. 2C As shown, the third auxiliary spacer element P3b has a material side surface close to the object side, an image side surface close to the image side, an outer diameter surface parallel to the optical axis and contacting the inner wall of the lens barrel, an inner diameter surface parallel to the optical axis and close to the optical axis, and at least one inclined surface with a certain inclination angle with respect to the optical axis, and the inclined surface is connected to the outer diameter surface. FIG. 2B As shown, the spacer elements of the optical imaging system 1002 further include a fixed element P4 disposed on the image side of the fourth lens E4, the fixed element P4 includes an outer diameter surface parallel to the optical axis, a material side surface close to the object side, and an image side surface close to the image side, the material side surface of the fixed element P4 at least partially contacts the edge of the image side of the fourth lens E4, and the outer diameter surface of the fixed element P4 at least partially contacts the inner wall of the lens barrel P0. The above-mentioned spacer elements can block the entry of external excess light, make the lens and the lens barrel better abut, and enhance the structural stability of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003.

[0123] As shown in FIG. 1, the optical imaging system 1001 includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4 and a fifth lens E5, which are sequentially arranged along the optical axis O. FIG. 2A and FIG. 2B As shown, when the first lens E1 and the second lens E2 adopt a stacking form, the first lens E1 and the second lens E2 are not in contact and are separated by the first spacer element P1, and the outer diameter surface of the first spacer element P1 and the first parallel surface of the inner wall of the lens barrel P0 are separated by a distance HP1 of 0 in the direction perpendicular to the optical axis. FIG. 2C As shown, the first lens E1 and the second lens E2 are provided with a snap-fit structure, and the outer diameter surface of the first spacer element P1 and the first parallel surface of the inner wall of the lens barrel P0 are separated by a distance HP1 of 0.2802 mm in the direction perpendicular to the optical axis.

[0124] Table 3 shows the basic parameters of the spacer elements and the lens barrel of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Example 1, and the units of the parameters in Table 3 are millimeters (mm).

[0125] Parameter / Optical Imaging System Optical Imaging System 1001 Optical Imaging System 1002 Optical Imaging System 1003 d1s 1.0449 1.0428 1.0412 D1s 2.0221 2.0521 1.7758 d2s 1.4884 1.4570 1.4636 D2s 2.7660 2.7560 2.7412 d3s 1.8666 1.8782 1.8210 D3s 3.4542 3.4142 3.4087 d0m 5.6810 5.4796 5.1325 D0s 2.1345 2.0940 2.7340 EP01 0.4878 0.4828 0.5278 CP1 0.0180 0.0180 0.0180 EP12 0.3446 0.3396 0.3546 CP2 0.0180 0.0200 0.0160 EP23 0.2531 0.2611 0.2551 CP3 0.0180 0.0180 0.0180 L 2.3000 2.4000 2.3500 ds 1.1639 1.1639 1.1639 H1 0.4100 0.4100 0.4601 D1 1.7809 1.7809 2.3541 HP1 0.0000 0.0000 0.2802

[0126] Table 3

[0127] FIG. 3A The on-axis chromatic aberration curves of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Example 1 are shown, which represent the deviation of light rays of different wavelengths from the convergent focal point after passing through the lens. FIG. 3B The astigmatism curves of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Example 1 are shown, which represent the meridional image curvature and sagittal image curvature. FIG. 3C The distortion curves of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Example 1 are shown, which represent the distortion size values corresponding to different image heights. FIG. 3D The magnification chromatic aberration curves of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Example 1 are shown, which represent the deviation of light rays on the imaging surface after passing through the lens at different image heights. According to FIG. 3A to FIG. 3D It can be seen that the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 given in Example 1 can achieve good imaging quality.

[0128] Embodiment 2

[0129] The following refers to FIG. 4A to FIG. 5D The optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 according to Example 2 of the present application are described. In this embodiment and the following embodiments, part of the description similar to Example 1 will be omitted for brevity. FIG. 4A to FIG. 4C The structural schematic diagrams of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 according to Example 2 of the present application are respectively shown.

[0130] As shown in FIG. 4A to FIG. 4C The optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 each include a lens barrel P0, lens groups E1-E4 and a plurality of spacer elements P1-P3c, respectively.

[0131] As shown in FIG. 4A to FIG. 4CAs shown, the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 employ the same lens group, which includes, in order from the object side to the image side, a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4. The first lens E1 has positive refractive power, the second lens E2 has positive refractive power, the third lens E3 has negative refractive power, and the fourth lens E4 has positive refractive power. The filter (not shown) has an object side surface S9 (not shown) and an image side surface S10 (not shown). Light from the object passes through the surfaces S1-S10 in order and is ultimately imaged on an image plane (not shown).

[0132] In the present example, the effective focal length f of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 is 2.62 mm, and the maximum field of view FOV of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 is 86.1°.

[0133] Table 4 shows the basic parameter table of the lens group of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2, wherein the units of the radius of curvature, the thickness and the effective focal length are all millimeters (mm). Tables 5-1 and 5-2 show the high-order term coefficients of the aspherical surfaces that can be used in the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2, wherein each aspherical surface type can be defined by the formula (1) given in Example 1 above.

[0134]

[0135] Table 4

[0136] Face No. A4 A6 A8 A10 A12 A14 A16 S1 5.8641E-03 1.9352E-04 -2.3692E-04 -1.8141E-05 -2.8134E-05 -2.3431E-08 -1.0360E-05 S2 -4.5025E-03 -3.8940E-03 -7.3310E-04 -1.4775E-04 -2.2745E-05 1.0230E-05 1.6433E-06 S3 -4.1365E-02 -5.0153E-03 -5.0740E-04 -7.5016E-05 -5.4934E-06 -6.9007E-07 9.9964E-06 S4 -6.8297E-02 8.4932E-03 2.4067E-03 7.0510E-05 -1.6120E-04 8.0624E-05 9.2982E-05 S5 -6.1791E-02 2.0874E-02 -4.1560E-03 -2.2504E-03 -1.1730E-03 -1.9990E-04 -1.8238E-04 S6 -1.9381E-01 9.6878E-02 -2.9452E-02 1.6721E-03 -3.8591E-04 1.1873E-03 -4.4595E-04 S7 -2.1350E+00 5.9345E-01 -1.8092E-01 4.8143E-02 -1.4161E-02 8.9380E-03 -4.9561E-03 S8 -2.2278E+00 3.1954E-01 -6.6783E-02 3.7835E-02 -1.0697E-02 2.6483E-04 -1.3579E-03

[0137] Table 5-1

[0138] Face No. A18 A20 A22 A24 A26 A28 A30 S1 -3.3474E-06 -2.5609E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S2 -1.1765E-06 -3.1298E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S3 2.3796E-06 4.2003E-07 1.6162E-06 3.7293E-06 3.4477E-06 1.9709E-06 -1.7611E-06 S4 3.8613E-05 2.1711E-05 -2.8393E-07 6.7325E-06 -3.3630E-06 -3.0267E-06 -7.0536E-06 S5 -8.8355E-05 -5.3138E-05 -1.6590E-05 -3.9367E-06 3.0033E-06 2.2353E-06 5.2899E-06 S6 5.3675E-05 -2.1716E-05 3.0273E-05 -4.0865E-06 2.0203E-06 1.2805E-06 -5.0550E-06 S7 1.8121E-03 -2.1456E-04 7.1230E-05 -2.7642E-04 2.1771E-04 -7.5797E-05 -1.6769E-06 S8 6.3829E-04 9.2289E-04 4.3034E-04 3.6398E-04 -9.3207E-06 6.5401E-05 -2.7241E-05

[0139] Table 5-2

[0140] As FIG. 4A to FIG. 4CAs shown, optical imaging systems 2001, 2002, and 2003 each include five spacer elements. These five spacer elements are a first spacer element P1, a second spacer element P2, a third spacer element P3, a third auxiliary spacer element P3b, and a fourth auxiliary spacer element P3c. The first spacer element P1 is located on the image-side of the first lens E1 and is at least partially in contact with the first lens E1; the second spacer element P2 is located on the image-side of the second lens E2 and is at least partially in contact with the second lens E2; the third spacer element P3 is located on the image-side of the third lens E3 and is at least partially in contact with the third lens E3; the third auxiliary spacer element P3b is located on the image-side of the third spacer element P3 and is at least partially in contact with the third spacer element P3; and the fourth auxiliary spacer element P3c is located on the image-side of the third auxiliary spacer element P3b and is at least partially in contact with the third auxiliary spacer element P3b.

[0141] like FIG. 4A to FIG. 4C As shown, the third auxiliary spacer element P3b has an object-side surface near the object side, an image-side surface near the image side, an outer diameter surface parallel to the optical axis and in contact with the inner wall of the lens barrel, an inner diameter surface parallel to and close to the optical axis, and at least one oblique contact surface at a certain angle to the optical axis, the oblique contact surface being connected to the outer diameter surface. FIG. 4B As shown, the spacer element of the optical imaging system 2002 also includes a fixing element P4 placed on the image-side surface of the fourth lens E4. The fixing element P4 includes an outer diameter surface parallel to the optical axis, an object-side surface near the object side, and an image-side surface near the image side. The object-side surface of the fixing element P4 is at least partially in contact with the edge of the image-side surface of the fourth lens E4, and the outer diameter surface of the fixing element P4 is at least partially in contact with the inner wall of the lens barrel P0. The aforementioned spacer element can block excess external light from entering, allowing the lens and lens barrel to better support each other, and enhancing the structural stability of the optical imaging systems 2001, 2002, and 2003.

[0142] like FIG. 4A and FIG. 4B As shown, when the first lens E1 and the second lens E2 are stacked, the first lens E1 and the second lens E2 are not in contact and are separated by the first spacer element P1. The distance HP1 between the outer diameter surface of the first spacer element P1 and the first parallel surface of the inner wall of the lens barrel P0 in the direction perpendicular to the optical axis is 0. FIG. 4C As shown, a fastening structure is provided between the first lens E1 and the second lens E2, and the distance HP1 between the outer diameter surface of the first spacer element P1 and the first parallel surface of the inner wall of the lens barrel P0 in the direction perpendicular to the optical axis is 0.2893mm.

[0143] Table 6 shows the basic parameters of the spacer elements and the lens barrel of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2, and the units of the parameters in Table 6 are millimeters (mm).

[0144] Parameter / Optical Imaging System Optical Imaging System 2001 Optical Imaging System 2002 Optical Imaging System 2003 d1s 1.0184 0.9978 1.0185 D1s 2.0921 2.0821 1.7756 d2s 1.2331 1.2387 1.2312 D2s 3.0060 2.9960 1.7792 d3s 1.9012 1.8912 1.8653 D3s 4.1019 4.0519 4.0660 d0m 5.1248 5.4696 5.2905 D0s 2.1616 2.1245 2.8921 EP01 0.4878 0.5411 0.4898 CP1 0.0180 0.0180 0.0160 EP12 0.2555 0.2355 0.2555 CP2 0.0180 0.0180 0.0200 EP23 0.3422 0.3422 0.3402 CP3 0.0180 0.0180 0.0160 L 2.3919 2.3000 2.2678 ds 1.1639 1.1539 1.1639 H1 0.4100 0.4100 0.4101 D1 1.7809 1.7709 2.3541 HP1 0.0000 0.0000 0.2893

[0145] Table 6

[0146] FIG. 5A The on-axis chromatic aberration curves of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2 are shown, which represent the deviation of light rays of different wavelengths from the convergent focal point after passing through the lens. FIG. 5B The astigmatism curves of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2 are shown, which represent the meridional image surface curvature and the sagittal image surface curvature. FIG. 5C The distortion curves of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2 are shown, which represent the distortion size values corresponding to different image heights. FIG. 5D The magnification chromatic aberration curves of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2 are shown, which represent the deviation of light rays on the imaging surface after passing through the lens at different image heights. According to FIG. 5A to FIG. 5D It can be known that the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 given by Example 2 can achieve good imaging quality.

[0147] Embodiment 3

[0148] The following refers to FIG. 6A to FIG. 7D The optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 according to Example 3 of the present application are described. FIG. 6A to FIG. 6C The structural schematic diagrams of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 according to Example 3 of the present application are respectively shown.

[0149] As shown in FIG. 6A to FIG. 6C The optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 each respectively include a lens barrel P0, lens groups E1-E4 and a plurality of spacer elements P1-P3b.

[0150] As shown in FIG. 6A to FIG. 6CAs shown, the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 employ the same lens group, which includes, in order from the object side to the image side, a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4. Among them, the first lens E1 has positive refractive power, the second lens E2 has negative refractive power, the third lens E3 has positive refractive power, and the fourth lens E4 has positive refractive power. The optical filter (not shown) has an object side surface S9 (not shown) and an image side surface S10 (not shown). Light from the object passes through each surface S1 to S10 in order and is finally imaged on the imaging surface (not shown).

[0151] In the present example, the effective focal length f of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 is 2.62 mm, and the maximum field of view FOV of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 is 86.0°.

[0152] Table 7 shows the basic parameter table of the lens group of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Example 3, wherein the units of the curvature radius, the thickness and the effective focal length are all millimeters (mm). Table 8-1 and Table 8-2 show the high-order term coefficients of the aspherical surface that can be used in each aspherical surface in Example 3, wherein each aspherical surface can be defined by the formula (1) given in Example 1 above.

[0153]

[0154] Table 7

[0155] Face No. A4 A6 A8 A10 A12 A14 S1 2.9049E-03 4.5125E-04 -1.6213E-04 1.2355E-05 -4.0458E-05 4.6906E-06 S2 5.1690E-03 -2.7805E-03 -6.8207E-04 -2.0277E-04 -6.6659E-05 -2.7730E-05 S3 -4.9207E-02 -1.5671E-03 4.0223E-04 -2.1682E-04 -7.7747E-05 -7.9733E-05 S4 -5.9650E-02 7.1356E-03 5.6467E-03 8.0228E-04 2.9859E-04 3.9142E-05 S5 -5.4746E-03 -1.1584E-02 8.7534E-03 -8.5958E-04 3.5945E-04 1.2797E-04 S6 -1.2286E-01 7.1652E-02 -2.9662E-02 7.8292E-03 -1.8682E-03 1.7540E-03 S7 -2.0149E+00 5.9602E-01 -1.6915E-01 3.2228E-02 -3.8597E-03 1.3616E-03 S8 -3.1470E+00 5.0613E-01 -1.1165E-01 4.2310E-02 -1.6114E-02 1.7204E-03

[0156] Table 8-1

[0157] Face No. A16 A18 A20 A22 A24 A26 S1 -8.1835E-06 1.9633E-06 -2.6610E-06 0.0000E+00 0.0000E+00 0.0000E+00 S2 -7.8436E-06 3.2346E-06 2.5789E-06 0.0000E+00 0.0000E+00 0.0000E+00 S3 -3.4518E-05 -1.2528E-05 -1.2448E-05 0.0000E+00 0.0000E+00 0.0000E+00 S4 -7.2070E-07 2.0854E-05 -8.1187E-06 -4.1675E-06 -8.1195E-06 0.0000E+00 S5 -8.1330E-05 4.5920E-05 -2.5875E-05 0.0000E+00 0.0000E+00 0.0000E+00 S6 -7.8957E-04 3.1199E-04 -4.9887E-05 3.8213E-05 0.0000E+00 0.0000E+00 S7 -2.7405E-03 1.6474E-03 -6.9533E-04 1.2210E-04 -2.5620E-05 0.0000E+00 S8 -3.5938E-03 2.8708E-05 -1.5572E-04 2.8601E-06 3.5876E-05 -7.7724E-05

[0158] Table 8-2

[0159] As FIG. 6A to FIG. 6CAs shown, the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 each include five spacer elements, which are the first spacer element P1, the second spacer element P2, the second auxiliary spacer element P2b, the third spacer element P3 and the third auxiliary spacer element P3b, respectively. The first spacer element P1 is disposed on the image side of the first lens E1 and at least partially contacts the first lens E1. The second spacer element P2 is disposed on the image side of the second lens E2 and at least partially contacts the second lens E2. The second auxiliary spacer element P2b is disposed on the image side of the second spacer element P2 and at least partially contacts the second spacer element P2. The third spacer element P3 is disposed on the image side of the third lens E3 and at least partially contacts the third lens E3. The third auxiliary spacer element P3b is disposed on the image side of the third spacer element P3 and at least partially contacts the third spacer element P3.

[0160] As shown in FIG. 3A, the second spacer element P2 and the third spacer element P3 each have a material side surface close to the object side, an image side surface close to the image side, an outer diameter surface parallel to the optical axis and contacting the inner wall of the lens barrel, an inner diameter surface parallel to the optical axis and close to the optical axis, and at least one inclined surface with a certain inclination angle with respect to the optical axis, and the inclined surface is connected to the outer diameter surface. FIG. 6A to FIG. 6C As shown in FIG. 3A, the second spacer element P2 and the third spacer element P3 each have a material side surface close to the object side, an image side surface close to the image side, an outer diameter surface parallel to the optical axis and contacting the inner wall of the lens barrel, an inner diameter surface parallel to the optical axis and close to the optical axis, and at least one inclined surface with a certain inclination angle with respect to the optical axis, and the inclined surface is connected to the outer diameter surface. FIG. 6B As shown in FIG. 3B, the spacer elements of the optical imaging system 3002 further include a fixed element P4 disposed on the image side of the fourth lens E4. The fixed element P4 includes an outer diameter surface parallel to the optical axis, an object side surface close to the object side, and an image side surface close to the image side. The object side surface of the fixed element P4 at least partially contacts the edge of the image side of the fourth lens E4, and the outer diameter surface of the fixed element P4 at least partially contacts the inner wall of the lens barrel P0. The above-mentioned spacer elements can block the entry of external excess light, make the lens better abut the lens barrel, and enhance the structural stability of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003.

[0161] As shown in FIG. 3A, the second spacer element P2 and the third spacer element P3 each have a material side surface close to the object side, an image side surface close to the image side, an outer diameter surface parallel to the optical axis and contacting the inner wall of the lens barrel, an inner diameter surface parallel to the optical axis and close to the optical axis, and at least one inclined surface with a certain inclination angle with respect to the optical axis, and the inclined surface is connected to the outer diameter surface. FIG. 6A As shown in FIG. 3A, the second spacer element P2 and the third spacer element P3 each have a material side surface close to the object side, an image side surface close to the image side, an outer diameter surface parallel to the optical axis and contacting the inner wall of the lens barrel, an inner diameter surface parallel to the optical axis and close to the optical axis, and at least one inclined surface with a certain inclination angle with respect to the optical axis, and the inclined surface is connected to the outer diameter surface. FIG. 6B As shown in FIG. 3A, the second spacer element P2 and the third spacer element P3 each have a material side surface close to the object side, an image side surface close to the image side, an outer diameter surface parallel to the optical axis and contacting the inner wall of the lens barrel, an inner diameter surface parallel to the optical axis and close to the optical axis, and at least one inclined surface with a certain inclination angle with respect to the optical axis, and the inclined surface is connected to the outer diameter surface. FIG. 6C As shown in FIG. 3A, the second spacer element P2 and the third spacer element P3 each have a material side surface close to the object side, an image side surface close to the image side, an outer diameter surface parallel to the optical axis and contacting the inner wall of the lens barrel, an inner diameter surface parallel to the optical axis and close to the optical axis, and at least one inclined surface with a certain inclination angle with respect to the optical axis, and the inclined surface is connected to the outer diameter surface.

[0162] Table 9 shows the basic parameters of the spacer elements and the lens barrel of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Example 3, and the units of the parameters in Table 9 are millimeters (mm).

[0163]

[0164]

[0165] Table 9

[0166] FIG. 7A The on-axis chromatic aberration curves of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Example 3 are shown, which represent the deviation of light rays of different wavelengths from the convergent focal point after passing through the lens. FIG. 7B The astigmatism curves of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Example 3 are shown, which represent the meridional image curvature and sagittal image curvature. FIG. 7C The distortion curves of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Example 3 are shown, which represent the distortion size values corresponding to different image heights. FIG. 7D The magnification chromatic aberration curves of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Example 3 are shown, which represent the deviation of light rays on the imaging plane after passing through the lens at different image heights. According to the formula FIG. 7A to FIG. 7D It can be seen that the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 given in Example 3 can achieve good imaging quality.

[0167] In summary, the optical imaging systems 1001, 1002, 1003, 2001, 2002, 2003, 3001, 3002 and 3003 of Example 1 to Example 3 satisfy the relationships shown in Table 10.

[0168] Conditional Expression / Optical Imaging System 1001 1002 1003 2001 2002 2003 3001 3002 3003 (d0m-D0s) / TD 1.67 1.60 1.13 1.37 1.55 1.11 1.48 1.58 1.15 (T12+CT2+T23) / (EP01+EP12) 0.65 0.66 0.61 0.82 0.79 0.82 0.84 0.86 0.87 |d1s / R2+d2s / R3| 0.24 0.25 0.25 0.23 0.22 0.23 0.14 0.13 0.15 ds / tan(FOV / 2) 1.25 1.25 1.25 1.25 1.24 1.25 1.28 1.28 1.28 H1 / L 0.18 0.17 0.20 0.17 0.18 0.18 0.19 0.18 0.18 (D1-D1s) / (CT1+CP1) -0.61 -0.69 1.46 -0.68 -0.68 1.26 -0.54 -0.62 1.55 (N2 / D2s+N3 / D3s) / EP23 4.18 4.08 4.19 2.70 2.72 3.77 4.13 4.07 4.15 (V2 / CP2) / (V3 / CP3) 0.51 0.45 0.57 2.91 2.91 2.33 0.47 0.46 0.46 (d3s / CP3) / (R6-R7)×T34 -20.99 -21.12 -20.48 -6.98 -6.95 -7.71 -0.32 -0.34 -0.31

[0169] Table 10

[0170] The present application also provides an imaging device, and the electronic photosensitive element thereof can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor device (CMOS). The imaging device can be a standalone imaging equipment such as a digital camera, or an imaging module integrated on a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging system described above.

[0171] The above description is only the preferred embodiment of the present application and the explanation of the technical principles. It should be understood by those skilled in the art that the scope of the disclosure of the present application is not limited to the technical solutions with the specific combination of the above technical features, and should also cover other technical solutions formed by combining the above technical features or their equivalent features without departing from the concept of the present application. For example, the technical solutions formed by replacing the above features with the technical features disclosed in the present application (but not limited to) with similar functions.

Claims

1. An optical imaging system, characterized in that, include: The lens group, along the optical axis from the object side to the image side, includes, in sequence: a first lens, a second lens, a third lens, and a fourth lens; Multiple spacer elements, including at least four spacer elements; and A lens barrel for accommodating the lens group and the plurality of spacer elements, wherein the lens barrel includes an object end face near the object side, an image end face near the image side, an outer wall, and an inner wall; in, The optical imaging system has four lenses with optical power. The effective focal length of the first lens is positive and is less than the effective focal length of other lenses with positive focal lengths. The second lens and the fourth lens both have negative optical power, and the third lens has positive optical power; or the optical power of the second lens and the third lens have opposite positive and negative attributes, and the fourth lens has positive optical power. The object-side surface of the first lens is convex, and the image-side surface is concave. The object-side surface of the second lens is concave. The object-side surface of the third lens is concave, and the image-side surface is convex. The object-side surface of the fourth lens is convex, and the image-side surface is concave; and The inner diameter d0m of the image end face of the lens barrel near the image side, the outer diameter D0s of the object end face of the lens barrel near the object side, and the distance TD from the object side surface of the first lens to the image side surface of the fourth lens on the optical axis satisfy: 1.1 < (d0m - D0s) / TD < 1.

7.

2. The optical imaging system according to claim 1, characterized in that, The distance from the effective diameter surface of the object side of the first lens to the image end face of the lens barrel near the image side along the optical axis gradually decreases from the center to the edge of the effective diameter surface of the object side of the first lens.

3. The optical imaging system according to claim 1, characterized in that, The radius of curvature R1 of the object side of the first lens, the radius of curvature R2 of the image side of the first lens, and the radius of curvature R3 of the object side of the second lens satisfy: R2 / R1>0 and R2 / R3<0.

4. The optical imaging system according to claim 1, 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, and the radius of curvature R2 of the image side of the first lens satisfy: R5 / R6>0 and R5 / R2<0.

5. The optical imaging system according to claim 1, characterized in that, The plurality of spacer elements includes a first spacer element disposed on the image-side surface of the first lens and in at least partial contact with the first lens; wherein, The first spacer element includes an object side surface near the object side, an image side surface near the image side, an inner diameter surface parallel to the optical axis, and an outer diameter surface parallel to the optical axis.

6. The optical imaging system according to claim 5, characterized in that, The inner wall of the lens barrel has a first parallel surface that is close to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element is in contact with the first parallel surface of the lens barrel.

7. The optical imaging system according to claim 5, characterized in that, The inner wall of the lens barrel has a first parallel surface that is close to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element is spaced apart from the first parallel surface of the inner wall of the lens barrel in a direction perpendicular to the optical axis.

8. The optical imaging system according to claim 5, characterized in that, The inner wall of the lens barrel has a first parallel surface that is close to the object side and parallel to the optical axis. The distance HP1 between the outer diameter surface of the first spacer element and the first parallel surface of the inner wall of the lens barrel in the direction perpendicular to the optical axis satisfies: 0mm≤HP1≤0.3001mm.

9. The optical imaging system according to any one of claims 1 to 8, characterized in that, The plurality of spacer elements includes a first spacer element disposed on the image-side surface of the first lens and in at least partial contact with the first lens, and a second spacer element disposed on the image-side surface of the second lens and in at least partial contact with the second lens; wherein... The air gap T12 between the first lens and the second lens on the optical axis, the air gap T23 between the second lens and the third lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the distance EP01 between the object end face of the lens barrel near the object side and the object side face of the first spacer element along the optical axis, and the distance EP12 between the first spacer element and the second spacer element along the optical axis satisfy: 0.6 < (T12 + CT2 + T23) / (EP01 + EP12) < 0.

9.

10. The optical imaging system according to any one of claims 1 to 8, characterized in that, The plurality of spacer elements includes a first spacer element disposed on the image-side surface of the first lens and in at least partial contact with the first lens, and a second spacer element disposed on the image-side surface of the second lens and in at least partial contact with the second lens; wherein... The inner diameter d1s of the object side of the first spacer element, the inner diameter d2s of the object side of the second spacer element, the radius of curvature R2 of the image side of the first lens, and the radius of curvature R3 of the object side of the second lens satisfy: 0.13≤|d1s / R2+d2s / R3|<0.

26.

11. The optical imaging system according to any one of claims 1 to 8, characterized in that, The minimum inner diameter ds of the front end portion of the lens barrel facing the object side satisfies the maximum field of view (FOV) of the optical imaging system as follows: 1.24mm≤ds / tan(FOV / 2)<1.3mm.

12. The optical imaging system according to any one of claims 1 to 8, characterized in that, The outer wall of the lens barrel has a first vertical plane perpendicular to the optical axis near the object side; wherein... The distance H1 from the object end face of the lens barrel near the object to the first vertical plane and the height L of the lens barrel along the optical axis satisfy: 0.17≤H1 / L<0.

25.

13. The optical imaging system according to any one of claims 1 to 8, characterized in that, The plurality of spacer elements includes a first spacer element disposed on the image-side surface of the first lens and in at least partial contact with the first lens; wherein, The maximum outer diameter D1 of the first lens, the outer diameter D1s of the object side of the first spacer element, the center thickness CT1 of the first lens on the optical axis, and the maximum thickness CP1 of the first spacer element along the optical axis satisfy: -0.7<(D1-D1s) / (CT1+CP1)≤1.

55.

14. The optical imaging system according to any one of claims 1 to 8, characterized in that, At least one of the plurality of spacers, located between the image-side surface of the third lens and the image-end surface of the lens barrel near the image-side surface, has a maximum thickness greater than 0.1 mm along the optical axis.

15. The optical imaging system according to any one of claims 1 to 8, characterized in that, The plurality of spacer elements includes a second spacer element disposed on the image-side surface of the second lens and in at least partial contact with the second lens, and a third spacer element disposed on the image-side surface of the third lens and in at least partial contact with the third lens; wherein... The refractive index N2 of the second lens, the refractive index N3 of the third lens, the outer diameter D2s of the object-side surface of the second spacer element, the outer diameter D3s of the object-side surface of the third spacer element, and the spacing EP23 between the second and third spacer elements along the optical axis satisfy: 2.70 mm. -2 ≤(N2 / D2s+N3 / D3s) / EP23≤4.19mm -2 .

16. The optical imaging system according to any one of claims 1 to 8, characterized in that, The plurality of spacer elements includes a second spacer element disposed on the image-side surface of the second lens and in at least partial contact with the second lens, and a third spacer element disposed on the image-side surface of the third lens and in at least partial contact with the third lens; wherein... The dispersion coefficient V2 of the second lens, the dispersion coefficient V3 of the third lens, the maximum thickness CP2 of the second spacer element along the optical axis, and the maximum thickness CP3 of the third spacer element along the optical axis satisfy: 0.45≤(V2 / CP2) / (V3 / CP3)≤2.

91.

17. The optical imaging system according to any one of claims 1 to 8, characterized in that, The plurality of spacer elements includes a third spacer element disposed on the image-side surface of the third lens and in at least partial contact with the third lens; wherein, The inner diameter d3s of the object side of the third spacer element, the maximum thickness CP3 of the third spacer element along the optical axis, 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, and the air gap T34 between the third lens and the fourth lens on the optical axis satisfy: -21.12≤(d3s / CP3) / (R6-R7)×T34≤-0.

31.

18. An optical imaging system, characterized in that, include: The lens group, along the optical axis from the object side to the image side, includes, in sequence: a first lens, a second lens, a third lens, and a fourth lens; A plurality of spacer elements, including at least four spacer elements, wherein a first spacer element is positioned on the image-side surface of the first lens and at least partially contacts the first lens, and a second spacer element is positioned on the image-side surface of the second lens and at least partially contacts the second lens; and A lens barrel for housing the lens group and the plurality of spacer elements; The optical imaging system has four lenses with optical power. The distance from the effective diameter surface of the object side of the first lens to the image end face of the lens barrel near the image side along the optical axis gradually decreases from the center to the edge of the effective diameter surface of the object side of the first lens. The effective focal length of the first lens is positive and is less than the effective focal length of other lenses with positive focal lengths. The second lens and the fourth lens both have negative optical power, and the third lens has positive optical power; or the optical power of the second lens and the third lens have opposite positive and negative attributes, and the fourth lens has positive optical power. The object-side surface of the first lens is convex, and the image-side surface is concave. The object-side surface of the second lens is concave. The object-side surface of the third lens is concave, and the image-side surface is convex. The object-side surface of the fourth lens is convex, and the image-side surface is concave; and The air gap T12 between the first lens and the second lens on the optical axis, the air gap T23 between the second lens and the third lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the distance EP01 between the object end face of the lens barrel near the object side and the object side face of the first spacer element along the optical axis, and the distance EP12 between the first spacer element and the second spacer element along the optical axis satisfy: 0.6 < (T12 + CT2 + T23) / (EP01 + EP12) < 0.

9.

19. The optical imaging system according to claim 18, characterized in that, The inner diameter d0m of the image end face of the lens barrel near the image side, the outer diameter D0s of the object end face of the lens barrel near the object side, and the distance TD from the object side surface of the first lens to the image side surface of the fourth lens on the optical axis satisfy: 1.1 < (d0m - D0s) / TD < 1.

7.

20. The optical imaging system according to claim 18, characterized in that, The distance from the effective diameter surface of the object side of the first lens to the image end face of the lens barrel near the image side along the optical axis gradually decreases from the center to the edge of the effective diameter surface of the object side of the first lens.

21. The optical imaging system according to claim 18, characterized in that, The radius of curvature R1 of the object side of the first lens, the radius of curvature R2 of the image side of the first lens, and the radius of curvature R3 of the object side of the second lens satisfy: R2 / R1>0 and R2 / R3<0.

22. The optical imaging system according to claim 18, 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, and the radius of curvature R2 of the image side of the first lens satisfy: R5 / R6>0 and R5 / R2<0.

23. The optical imaging system according to claim 18, characterized in that, The first spacer element includes an object side surface near the object side, an image side surface near the image side, an inner diameter surface parallel to the optical axis, and an outer diameter surface parallel to the optical axis.

24. The optical imaging system according to claim 23, characterized in that, The inner wall of the lens barrel has a first parallel surface that is close to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element is in contact with the first parallel surface of the lens barrel.

25. The optical imaging system according to claim 23, characterized in that, The inner wall of the lens barrel has a first parallel surface that is close to the object side and parallel to the optical axis, and the outer diameter surface of the first spacer element is spaced apart from the first parallel surface of the inner wall of the lens barrel in a direction perpendicular to the optical axis.

26. The optical imaging system according to claim 23, characterized in that, The inner wall of the lens barrel has a first parallel surface that is close to the object side and parallel to the optical axis. The distance HP1 between the outer diameter surface of the first spacer element and the first parallel surface of the inner wall of the lens barrel in the direction perpendicular to the optical axis satisfies: 0mm≤HP1≤0.3001mm.

27. The optical imaging system according to any one of claims 18 to 26, characterized in that, The inner diameter d1s of the object side of the first spacer element, the inner diameter d2s of the object side of the second spacer element, the radius of curvature R2 of the image side of the first lens, and the radius of curvature R3 of the object side of the second lens satisfy: 0.13≤|d1s / R2+d2s / R3|<0.

26.

28. The optical imaging system according to any one of claims 18 to 26, characterized in that, The minimum inner diameter ds of the front end portion of the lens barrel facing the object side satisfies the maximum field of view (FOV) of the optical imaging system as follows: 1.24mm≤ds / tan(FOV / 2)<1.3mm.

29. The optical imaging system according to any one of claims 18 to 26, characterized in that, The outer wall of the lens barrel has a first vertical plane perpendicular to the optical axis near the object side; wherein... The distance H1 from the object end face of the lens barrel near the object to the first vertical plane and the height L of the lens barrel along the optical axis satisfy: 0.17≤H1 / L<0.

25.

30. The optical imaging system according to any one of claims 18 to 26, characterized in that, The maximum outer diameter D1 of the first lens, the outer diameter D1s of the object side of the first spacer element, the center thickness CT1 of the first lens on the optical axis, and the maximum thickness CP1 of the first spacer element along the optical axis satisfy: -0.7<(D1-D1s) / (CT1+CP1)≤1.

55.

31. The optical imaging system according to any one of claims 18 to 26, characterized in that, At least one of the plurality of spacers, located between the image-side surface of the third lens and the image-end surface of the lens barrel near the image-side surface, has a maximum thickness greater than 0.1 mm along the optical axis.

32. The optical imaging system according to any one of claims 18 to 26, characterized in that, The plurality of spacer elements further includes a third spacer element disposed on the image-side surface of the third lens and in at least partial contact with the third lens; wherein, The refractive index N2 of the second lens, the refractive index N3 of the third lens, the outer diameter D2s of the object-side surface of the second spacer element, the outer diameter D3s of the object-side surface of the third spacer element, and the spacing EP23 between the second and third spacer elements along the optical axis satisfy: 2.70 mm. -2 ≤(N2 / D2s+N3 / D3s) / EP23≤4.19mm -2 .

33. The optical imaging system according to any one of claims 18 to 26, characterized in that, The plurality of spacer elements further includes a third spacer element disposed on the image-side surface of the third lens and in at least partial contact with the third lens; wherein, The dispersion coefficient V2 of the second lens, the dispersion coefficient V3 of the third lens, the maximum thickness CP2 of the second spacer element along the optical axis, and the maximum thickness CP3 of the third spacer element along the optical axis satisfy: 0.45≤(V2 / CP2) / (V3 / CP3)≤2.

91.

34. The optical imaging system according to any one of claims 18 to 26, characterized in that, The plurality of spacer elements includes a third spacer element disposed on the image-side surface of the third lens and in at least partial contact with the third lens; wherein, The inner diameter d3s of the object side of the third spacer element, the maximum thickness CP3 of the third spacer element along the optical axis, 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, and the air gap T34 between the third lens and the fourth lens on the optical axis satisfy: -21.12≤(d3s / CP3) / (R6-R7)×T34≤-0.31.

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