Optical imaging lens

Abstract

The application discloses an optical imaging lens, which comprises an imaging lens group, the imaging lens group comprises a lens group and a spacer element group, the lens group is composed of a first lens, a second lens, a third lens and a fourth lens arranged in sequence from an object side to an image side along a first optical axis; the spacer element group comprises a first spacer element and a second spacer element; the optical imaging lens satisfies 6.74 < EP12 / T12 < 12.80 and 31.30 < CT2 / (T23+CP2) < 40.15, wherein EP12 is the distance of the first spacer element and the second spacer element along the first optical axis direction, T12 is the interval distance of the first lens and the second lens on the first optical axis, CT2 is the center thickness of the second lens on the first optical axis, T23 is the interval distance of the second lens and the third lens on the first optical axis, and CP2 is the maximum thickness of the second spacer element.

Description

Technical Field

[0001] This application relates to the field of optical devices, and particularly to an optical imaging lens. Background Art

[0002] With the rapid development of portable devices such as smart phones, telephoto lenses have been widely used due to their advantages of clearly imaging distant objects, having a large magnification ratio, and being able to present the detailed features of objects.

[0003] The total effective focal length of an optical imaging lens is an important criterion for measuring whether an optical imaging lens is a telephoto lens. The larger the total effective focal length of an optical imaging lens, the clearer the distant objects photographed by the optical imaging lens. However, the larger the total effective focal length of an optical imaging lens, the greater the optical path required by the optical imaging lens. Therefore, in order to achieve the telephoto characteristics of an optical imaging lens, the overall length of existing optical imaging lenses is usually large, which will limit the application of optical imaging lenses in portable devices. Currently, miniaturization of optical imaging lenses is an important development trend. However, in the prior art, while achieving the miniaturization of an optical imaging lens, it often affects the imaging quality or assembly stability of the optical imaging lens, etc. Summary of the Invention

[0004] This application provides an optical imaging lens, including an imaging lens group, a prism, and an imaging surface. The imaging lens group and the imaging surface are located on the same side of the prism; the imaging lens group includes a lens barrel and a lens group and a spacer element group accommodated in the lens barrel. The lens group is composed of a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a negative optical power, and a fourth lens with a positive optical power arranged in sequence from the object side to the image side along the first optical axis. The central thickness of the second lens on the first optical axis is greater than the central thickness of any other lens except the second lens in the imaging lens group on the first optical axis; the spacer element group includes a first spacer element and a second spacer element. The first spacer element is placed between the first lens and the second lens and contacts the image side surface of the first lens. The second spacer element is placed between the second lens and the third lens and contacts the image side surface of the second lens; and the optical imaging lens satisfies: 6.74 < EP12 / T12 < 12.80 and 31.30 < CT2 / (T23 + CP2) <  40.15, where EP12 is the distance between the first spacer element and the second spacer element along the first optical axis, T12 is the spacing distance between the first lens and the second lens on the first optical axis, CT2 is the central thickness of the second lens on the first optical axis, T23 is the spacing distance between the second lens and the third lens on the first optical axis, and CP2 is the maximum thickness of the second spacer element.

[0005] According to an exemplary embodiment of the present application, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 0.92 < R5 / D2m < 8.80 and 1.28 < d3s / R6 < 1.59, where R5 is the curvature radius of the object side surface of the third lens, R6 is the curvature radius of the image side surface of the third lens, D2m is the outer diameter of the image side surface of the second spacer element, and d3s is the inner diameter of the object side surface of the third spacer element.

[0006] According to an exemplary embodiment of the present application, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 2.40 < EP23 / CT3 < 3.17, where EP23 is the distance between the second spacer element and the third spacer element along the first optical axis direction, and CT3 is the central thickness of the third lens on the first optical axis.

[0007] According to an exemplary embodiment of the present application, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 0.65 < SAG41 / (CT4 + CP3) < 1.47, where SAG41 is the axial distance between the intersection of the object side surface of the fourth lens and the first optical axis and the vertex of the effective radius of the object side surface of the fourth lens, CT4 is the central thickness of the fourth lens on the first optical axis, and CP3 is the maximum thickness of the third spacer element.

[0008] According to an exemplary embodiment of the present application, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: -13.25 < f4 / f3 < -1.26 and 1.10 < (CP3 + CT4) / CT3 < 2.69, where f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, CP3 is the maximum thickness of the third spacer element, CT3 is the central thickness of the third lens on the first optical axis, and CT4 is the central thickness of the fourth lens on the first optical axis.

[0009] According to an exemplary embodiment of the present application, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 1.72 < EP23 / SAG32 < 2.90, where EP23 is the distance between the second spacer element and the third spacer element along the first optical axis direction, and SAG32 is the axial distance between the intersection of the image side surface of the third lens and the first optical axis and the vertex of the effective radius of the image side surface of the third lens.

[0010] According to an exemplary embodiment of the present application, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 0.72 < R7 / R8 < 1.10 and 1.51 < d3m / R7 < 2.40, where R7 is the radius of curvature of the object side surface of the fourth lens, R8 is the radius of curvature of the image side surface of the fourth lens, and d3m is the inner diameter of the image side surface of the third spacer element.

[0011] According to an exemplary embodiment of the present application, the spacer element group further includes a second auxiliary spacer element, which is disposed on the image side of the second spacer element and contacts the image side surface of the second spacer element; the optical imaging lens satisfies: 6.50 < (CP2 + CP2b) / T23 < 11.75, where CP2b is the maximum thickness of the second auxiliary spacer element.

[0012] According to an exemplary embodiment of the present application, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; and the maximum outer diameter of the first spacer element is greater than the maximum outer diameter of the second spacer element, and the maximum outer diameter of the second spacer element is greater than the maximum outer diameter of the third spacer element; the minimum inner diameter of the second spacer element is less than the minimum inner diameter of any one of the spacer elements other than the second spacer element in the spacer element group.

[0013] According to an exemplary embodiment of the present application, the optical imaging lens satisfies: -24.50 < f1 / D1s < -20.50, where f1 is the effective focal length of the first lens and D1s is the outer diameter of the object side surface of the first spacer element.

[0014] According to an exemplary embodiment of the present application, the optical imaging lens satisfies: 0.60 < (CT2 - CT1) / EP12 < 1.40, where CT1 is the central thickness of the first lens on the first optical axis.

[0015] According to an exemplary embodiment of the present application, the optical imaging lens satisfies: 1.09 < f2 / d2s < 2.30 and 1.41 < D1m / R3 < 1.90, where f2 is the effective focal length of the second lens, d2s is the inner diameter of the object side surface of the second spacer element, D1m is the outer diameter of the image side surface of the first spacer element, and R3 is the radius of curvature of the object side surface of the second lens.

[0016] According to an exemplary embodiment of the present application, the optical imaging lens satisfies: 4.50 < CT2 / CT3 < 5.40 and -2.00 < f3 / d2m < -1.25, where CT3 is the central thickness of the third lens on the first optical axis, f3 is the effective focal length of the third lens, and d2m is the inner diameter of the image side surface of the second spacer element.

[0017] According to an exemplary embodiment of the present application, the optical imaging lens satisfies: 1.20 < d0s / d0m < 2.00, where d0s is the inner diameter of the object-side end face of the lens barrel, and d0m is the inner diameter of the image-side end face of the lens barrel.

[0018] According to an exemplary embodiment of the present application, the optical imaging lens satisfies: 2.80 < f / L < 3.30, where f is the total effective focal length of the optical imaging lens, and L is the maximum length of the lens barrel along the first optical axis direction.

[0019] According to an exemplary embodiment of the present application, the object-side surface of the first lens is convex, and the image-side surface is concave; the object-side surface of the second lens is convex; the object-side surface of the third lens is convex, and the image-side surface is concave; the object-side surface of the fourth lens is convex, and the image-side surface is concave.

[0020] By providing a prism in the optical imaging lens provided in the present application, light can be reflected multiple times inside the prism, achieving the characteristics of a long focal length of the optical imaging lens while meeting the miniaturization of the optical imaging lens. When the central thickness of the second lens on the optical axis is the largest, it is easy to cause appearance problems due to uneven thickness ratio, and then cause unstable assembly. By controlling EP12 / T12 and CT2 / (T23 + CP2) within a reasonable range, the distance between the second lens and the third lens can be adjusted to avoid the assembly collision problem caused by too small distance between the second lens and the third lens, and improve the assembly stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects, and advantages of the present application will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings. Among them:

[0022] [[ID=ID=18]] Figure 1 A schematic diagram showing some parameters of an optical imaging lens of the present application;

[0023] Figure 2 A schematic diagram showing the structure of an optical imaging lens of the present application;

[0024] Figure 3 A schematic diagram showing a partial structure of the optical imaging lens according to Embodiment 1 of the present application;

[0025] Figure 4 A schematic diagram showing a partial structure of the optical imaging lens according to Embodiment 2 of the present application;

[0026] Figure 5 A schematic diagram showing a partial structure of the optical imaging lens according to Embodiment 3 of the present application;

[0027] Figure 6The astigmatism curve (A1), distortion curve (B1), and relative illumination curve (C1) of the optical imaging lenses of Embodiments 1, 2, and 3 of this application are shown.

[0028] Figure 7 A partial structural schematic diagram of the optical imaging lens of Embodiment 4 of this application is shown;

[0029] Figure 8 A partial structural schematic diagram of the optical imaging lens of Embodiment 5 of this application is shown;

[0030] Figure 9 A partial structural schematic diagram of the optical imaging lens of Embodiment 6 of this application is shown;

[0031] Figure 10 The astigmatism curve (A2), distortion curve (B2), and relative illumination curve (C2) of the optical imaging lenses of Embodiments 4, 5, and 6 of this application are shown.

[0032] Figure 11 A partial structural schematic diagram of the optical imaging lens of Embodiment 7 of this application is shown;

[0033] Figure 12 A partial structural schematic diagram of the optical imaging lens of Embodiment 8 of this application is shown;

[0034] Figure 13 A partial structural schematic diagram of the optical imaging lens of Embodiment 9 of this application is shown;

[0035] Figure 14 The astigmatism curve (A3), distortion curve (B3), and relative illumination curve (C3) of the optical imaging lenses of Embodiments 7, 8, and 9 of this application are shown.

[0036] Figure 15 The modulation transfer function (MTF) curves of the optical imaging lens of this application are shown when EP12 / T12=9.01 and CT2 / (T23+CP2)=20.

[0037] Figure 16 The MTF curves of the optical imaging lens of this application are shown when EP12 / T12=9.01 and CT2 / (T23+CP2)=55;

[0038] Figure 17 The MTF curves of the optical imaging lens of this application are shown when EP12 / T12=9.01 and CT2 / (T23+CP2)=32.83. Detailed Implementation

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

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

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

[0042] In this text, if a lens surface is convex and its location is not defined, it means that the lens surface is convex at least in the paraxial region; if a lens surface is concave and its location is not defined, it means that the lens surface is concave at least in the paraxial region. The paraxial region refers to the region near the optical axis. The surface of each lens closest to the object side is the object-side surface of the lens, and the surface closest to the image side is the image-side surface of the lens.

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

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

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other. The following embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. For example, the elements in the various embodiments of this application can be arbitrarily combined.

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

[0047] Figure 1 A schematic diagram illustrating some parameters of an optical imaging lens according to this application is provided to facilitate a better understanding of this application. Figure 1 As shown, d0s is the inner diameter of the object-side end face of the lens barrel, D1s is the outer diameter of the object-side side of the first spacer element, d2s is the inner diameter of the object-side side of the second spacer element, d3s is the inner diameter of the object-side side of the third spacer element, d3m is the inner diameter of the image-side side of the third spacer element, d2m is the inner diameter of the image-side side of the second spacer element, d0m is the inner diameter of the image-side end face of the lens barrel, D2m is the outer diameter of the image-side side of the second spacer element, D1m is the outer diameter of the image-side side of the first spacer element, CP2 is the maximum thickness of the second spacer element, CP3 is the maximum thickness of the third spacer element, CP2b is the maximum thickness of the second auxiliary spacer element, EP12 is the distance between the first spacer element and the second spacer element along the first optical axis, EP23 is the distance between the second spacer element and the third spacer element along the first optical axis, and L is the maximum length of the lens barrel along the first optical axis.

[0048] Figure 2 An exemplary schematic diagram of the structure of an optical imaging lens according to this application is shown. Figure 2 As shown, the optical imaging lens provided in this application may include an imaging lens group, a prism T, and an imaging plane IMA. The imaging lens group and the imaging plane IMA are located on the same side of the prism T and are spaced apart from each other.

[0049] In an exemplary implementation, reference Figure 2 The prism may have a first surface 101 and a second surface 102 that are parallel to each other, and may also have at least one reflecting surface (e.g., 103 or 104) for connecting the first surface 101 and the second surface 102.

[0050] In an exemplary implementation, reference Figure 2The imaging lens group and the imaging surface IMA are located on the side of the prism T closest to its second surface 102 and are spaced apart from each other. The image side of the imaging lens group faces the second surface 102 of the prism T. A portion of the structure of the prism T and the imaging lens group are arranged along the first optical axis, and another portion of the structure of the prism T and the imaging surface IMA are arranged along the second optical axis, with the first optical axis and the second optical axis being parallel.

[0051] In an exemplary embodiment, the second surface of the prism may include an incident area, a reflection area, and an exit area spaced apart.

[0052] In an exemplary embodiment, light rays emitted from the fourth lens can enter the prism along the first optical axis through the incident area of ​​the second surface of the prism, and undergo multiple reflections inside the prism. After multiple reflections, the light rays then exit along the second optical axis through the exit area of ​​the second surface of the prism.

[0053] In an exemplary implementation, reference Figure 2 The prism T can be a trapezoidal prism. The prism T can have a first surface 101 and a second surface 102 that are parallel to each other, and a first reflecting surface 103 and a second reflecting surface 104 connecting the first surface 101 and the second surface 102. The aperture of the first surface 101 of the prism can be smaller than the aperture of the second surface 102 of the prism.

[0054] In an exemplary embodiment, light rays emitted from the fourth lens can enter the prism along the first optical axis via the incident area of ​​the second surface of the prism, and be redirected to the reflection area of ​​the second surface by the first reflecting surface of the prism for the first total internal reflection, then redirected to the second reflecting surface of the prism by the reflection area of ​​the second surface for the second total internal reflection, and then redirected to the exit area of ​​the second surface by the second reflecting surface of the prism for the third total internal reflection, and then exit along the second optical axis via the exit area of ​​the second surface of the prism.

[0055] It should be noted that the three reflections of light inside the prism are merely an example; it could also be five, seven, or other times. The number of reflections inside the prism is related to the aperture sizes of the first and second surfaces of the prism, as well as the distance between the first and second surfaces. The prism structure can be adjusted to change the number of reflections as needed, and this application does not impose any specific limitations on this.

[0056] The optical imaging lens provided in this application, by setting a prism, allows light to be reflected multiple times inside the prism, thus achieving the telephoto characteristics of the optical imaging lens while satisfying the requirements of miniaturization.

[0057] In an exemplary embodiment, the imaging lens group includes a lens assembly consisting of a first lens, a second lens, a third lens, and a fourth lens arranged sequentially along a first optical axis from the object side to the image side. Each lens has an effective diameter region capable of transmitting light and a non-effective diameter region surrounding the effective diameter region that cannot transmit light. In the first to fourth lenses, any two adjacent lenses may have a gap distance along the first optical axis, which can be an air gap.

[0058] In an exemplary embodiment, the first lens has negative optical power. The object-side surface of the first lens is convex, and the image-side surface is concave.

[0059] In an exemplary embodiment, the second lens has positive optical power. The object-side surface of the second lens is convex, and the image-side surface is either convex or concave. The second lens with positive optical power has the function of converging light rays.

[0060] In an exemplary embodiment, the third lens has negative optical power. The object-side surface of the third lens is convex, and the image-side surface is concave.

[0061] In an exemplary embodiment, the fourth lens has positive optical power. The object-side surface of the fourth lens is convex, and the image-side surface is concave.

[0062] In an exemplary embodiment, the imaging lens group further includes a spacer element group, which may include at least one spacer element disposed between the lenses and located in the non-effective diameter region of the lenses. It should be understood that this application does not specifically limit the number of spacer elements; at least one spacer element may be disposed between any two adjacent lenses, and the entire optical imaging lens may include any number of spacer elements. Spacer elements help the optical imaging lens intercept excess reflective light paths, reduce stray light and ghosting, and improve image quality.

[0063] In an exemplary embodiment, the optical imaging lens further includes a lens barrel. A lens group and a spacer element group are disposed within the lens barrel. The lens barrel includes an object-side end face, an image-side end face, an outer annular surface, and an inner annular surface, wherein the end face of the lens barrel closest to the object side is the object-side end face of the lens barrel, and the end face of the lens barrel closest to the image side is the image-side end face of the lens barrel; in a direction perpendicular to the first optical axis, the surface of the lens barrel furthest from the first optical axis is the outer annular surface, and the surface of the lens barrel closest to the first optical axis is the inner annular surface.

[0064] In an exemplary embodiment, the optical imaging lens may further include an aperture stop for limiting the light beam. The aperture stop helps to concentrate the light entering the optical lens, reduce the maximum aperture of the optical lens, and decrease the assembly sensitivity of the system, thereby further improving the imaging quality of the optical lens. It should be noted that the aperture stop can be positioned between or on one side of any lens, depending on actual needs. Exemplarily, the aperture stop is positioned on the image side of the fourth lens.

[0065] In an exemplary embodiment, the optical imaging lens may further include a filter for correcting color deviation. Exemplarily, referring to Figure 2 , the filter P is disposed between the second surface 102 of the prism T and the imaging surface IMA. It can be understood that the light rays exiting from the exit region of the second surface 102 of the prism T are projected onto the imaging surface IMA after passing through the filter P.

[0066] In an exemplary embodiment, the central thickness of the second lens on the first optical axis is greater than the central thickness of any other lens in the imaging lens group except the second lens on the first optical axis; the spacer element group includes a first spacer element and a second spacer element. The first spacer element is disposed between the first lens and the second lens and is in contact with the image side surface of the first lens, and the second spacer element is disposed between the second lens and the third lens and is in contact with the image side surface of the second lens; and the optical imaging lens satisfies: 6.74 < EP12 / T12 < 12.80 and 31.30 < CT2 / (T23 + CP2) < 40.15, where EP12 is the distance between the first spacer element and the second spacer element along the first optical axis, T12 is the spacing distance between the first lens and the second lens on the first optical axis, CT2 is the central thickness of the second lens on the first optical axis, T23 is the spacing distance between the second lens and the third lens on the first optical axis, and CP2 is the maximum thickness of the second spacer element. When the central thickness of the second lens on the optical axis is the largest, it is easy to have appearance problems due to uneven thickness ratio, and then the assembly instability occurs. By controlling EP12 / T12 and CT2 / (T23 + CP2) within a reasonable range, the distance between the second lens and the third lens can be adjusted to avoid the assembly collision problem caused by too small distance between the second lens and the third lens, improve the assembly stability, and also avoid the problems of weak lens strength, push-off force and temperature term reliability caused by too thin central thickness of the second lens. It can also effectively ensure the thickness ratio of the second lens, facilitate the molding of the second lens, avoid appearance problems caused by uneven thickness ratio, and then avoid the phenomenon of stray light, ensuring the imaging quality of the optical imaging lens.

[0067] Figure 15 Shows the modulation transfer function (MTF) curve of the optical imaging lens of the present application when EP12 / T12 = 9.01 and CT2 / (T23 + CP2) = 20.

[0068] Figure 16 Shows the MTF curve of the optical imaging lens of the present application when EP12 / T12 = 9.01 and CT2 / (T23 + CP2) = 55.

[0069] Figure 17The MTF curves of the optical imaging lens of this application are shown when EP12 / T12=9.01 and CT2 / (T23+CP2)=32.83.

[0070] Figure 15 The optical imaging lens in this application meets the limitations of condition EP12 / T12, which satisfies the condition that the center thickness of the second lens on the optical axis is the largest. However, at this point, uneven thickness ratio can easily cause appearance problems, leading to assembly instability. Furthermore, since condition CT2 / (T23+CP2) is smaller than the limitations of this application, the center thickness of the second lens is too thin, which can easily cause problems with lens strength, push-out force, and temperature reliability. This is detrimental to the formation of the second lens and can also easily cause appearance problems due to uneven thickness ratio, leading to stray light phenomena and affecting the imaging quality of the optical imaging lens. Figure 15 As can be seen, the MTF curves are quite dispersed.

[0071] Figure 16 The optical imaging lens in this application meets the limitations of condition EP12 / T12, satisfying the condition where the center thickness of the second lens on the optical axis is the largest. However, at this point, uneven thickness ratio can easily cause appearance problems, leading to assembly instability. Furthermore, because condition CT2 / (T23+CP2) exceeds the limitations of this application, the distance between the second and third lenses becomes too small, causing assembly collision problems, resulting in poor assembly stability and affecting the imaging quality of the optical imaging lens. Figure 16 As can be seen, the MTF curves are quite dispersed.

[0072] Figure 17 The optical imaging lens in this application meets the limitations of condition EP12 / T12, which satisfies the condition that the center thickness of the second lens on the optical axis is at its maximum. However, at this point, uneven thickness ratio can easily lead to appearance problems and instability in assembly. By controlling condition CT2 / (T23+CP2) to meet the limitations of this application, the distance between the second and third lenses can be adjusted, avoiding assembly collision problems caused by an excessively small distance between the second and third lenses, thus improving assembly stability. It can also avoid problems such as weak lens strength, push-off force, and temperature reliability caused by an excessively thin center thickness of the second lens. Furthermore, it can effectively ensure the thickness ratio of the second lens, which is beneficial for the formation of the second lens, avoiding appearance problems caused by uneven thickness ratio, thus avoiding stray light phenomena and improving the imaging quality of the optical imaging lens. Figure 17 As can be seen, the MTF curves are relatively concentrated.

[0073] In an exemplary embodiment, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 0.92 < R5 / D2m < 8.80 and 1.28 < d3s / R6 < 1.59, where R5 is the curvature radius of the object side surface of the third lens, R6 is the curvature radius of the image side surface of the third lens, D2m is the outer diameter of the image side surface of the second spacer element, and d3s is the inner diameter of the object side surface of the third spacer element. By adjusting the curvature radius of the third lens, the surface optical sensitivity can be reduced, which is beneficial to surface processing; by restricting the inner diameter of the object side surface of the third spacer element and the outer diameter of the image side surface of the second spacer element, the outer diameter of the third spacer element can be effectively controlled to be smaller, while ensuring the assembly stability of the optical imaging lens.

[0074] In an exemplary embodiment, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 2.40 < EP23 / CT3 < 3.17, where EP23 is the distance between the second spacer element and the third spacer element along the first optical axis direction, and CT3 is the central thickness of the third lens on the first optical axis. By controlling the above conditions, it is beneficial for the edge part of the third lens to transition smoothly, which is beneficial to injection molding and improves the production yield.

[0075] In an exemplary embodiment, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 0.65 < SAG41 / (CT4 + CP3) < 1.47, where SAG41 is the axial distance between the intersection of the object side surface of the fourth lens and the first optical axis and the vertex of the effective radius of the object side surface of the fourth lens, CT4 is the central thickness of the fourth lens on the first optical axis, and CP3 is the maximum thickness of the third spacer element. By controlling the above conditions, the height of the marginal rays can be effectively reduced, avoiding stray light caused by excessive ray height. At the same time, on the premise of ensuring the miniaturization of the optical imaging lens, the structural space is reasonably allocated to ensure the minimum bearing required for assembly and improve the stability of the optical imaging lens in high-temperature and high-humidity environments.

[0076] In an exemplary embodiment, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: -13.25 < f4 / f3 < -1.26 and 1.10 < (CP3 + CT4) / CT3 < 2.69, where f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, CP3 is the maximum thickness of the third spacer element, CT3 is the central thickness of the third lens on the first optical axis, and CT4 is the central thickness of the fourth lens on the first optical axis. When the difference between the effective focal length of the third lens and the effective focal length of the fourth lens is large, the shapes of the third lens and the fourth lens are also quite different. However, by controlling the central thickness of the third lens on the first optical axis and the central thickness of the fourth lens on the first optical axis, it is beneficial to the assembly stability of the third lens and the fourth lens and avoids reliability problems such as dropping.

[0077] In an exemplary embodiment, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 1.72 < EP23 / SAG32 < 2.90, where EP23 is the distance between the second spacer element and the third spacer element along the first optical axis, and SAG32 is the axial distance between the intersection of the image side surface of the third lens and the first optical axis and the effective radius vertex of the image side surface of the third lens. By controlling the axial distance between the intersection of the image side surface of the third lens and the first optical axis and the effective radius vertex of the image side surface of the third lens, the height of the third lens can be effectively constrained, avoiding excessive bending of the lens, reducing the processing difficulty, and at the same time enabling the optical imaging lens to have a better ability to balance chromatic aberration and distortion; and by controlling the above conditional formula, the edge thickness of the third lens is ensured, which is beneficial to improving the assembly stability and the yield.

[0078] In an exemplary embodiment, the spacer element group further includes a third spacer element, which is disposed between the third lens and the fourth lens and contacts the image side surface of the third lens; the optical imaging lens satisfies: 0.72 < R7 / R8 < 1.10 and 1.51 < d3m / R7 < 2.40, where R7 is the curvature radius of the object side surface of the fourth lens, R8 is the curvature radius of the image side surface of the fourth lens, and d3m is the inner diameter of the image side surface of the third spacer element. The ratio of the curvature radius of the object side surface and the image side surface of the fourth lens within a small range ensures that the left and right two sides of the fourth lens bend in the same direction and have a small difference, ensuring good injection molding conditions; and the smaller inner diameter of the image side surface of the third spacer element is beneficial to reducing the exit aperture, and thus beneficial to the miniaturization of the optical imaging lens.

[0079] In an exemplary embodiment, the spacer element group further includes a second auxiliary spacer element, which is placed on the image side of the second spacer element and contacts the image side surface of the second spacer element; the optical imaging lens satisfies: 6.50 < (CP2 + CP2b) / T23 < 11.75, where CP2b is the maximum thickness of the second auxiliary spacer element, T23 is the spacing distance between the second lens and the third lens on the first optical axis, and CP2 is the maximum thickness of the second spacer element. By controlling the above conditions, it is beneficial to adjust the stray light generated by the inner diameter of the spacer element, while ensuring the abutment of the front and rear lenses, improving the imaging quality while taking into account the assembly stability.

[0080] In an exemplary embodiment, the spacer element group further includes a third spacer element, which is placed between the third lens and the fourth lens and contacts the image side surface of the third lens; and the maximum outer diameter of the first spacer element is greater than the maximum outer diameter of the second spacer element, and the maximum outer diameter of the second spacer element is greater than the maximum outer diameter of the third spacer element; the minimum inner diameter of the second spacer element is less than the minimum inner diameter of any one of the spacer elements other than the second spacer element in the spacer element group. From the outer diameter of the first spacer element to the outer diameter of the third spacer element, the outer diameters of the spacer elements decrease in sequence, which is beneficial for the optical imaging lens to achieve miniaturization. By adjusting the inner diameter of the second spacer element, stray light other than the effective light can be avoided, and the imaging quality can be improved.

[0081] It should be noted that the maximum outer diameter of the spacer element refers to the maximum outer diameter of the object side surface and the image side surface of the spacer element; the minimum inner diameter of the spacer element refers to the minimum inner diameter of the object side surface and the image side surface of the spacer element.

[0082] In an exemplary embodiment, the optical imaging lens satisfies: -24.50 < f1 / D1s < -20.50, where f1 is the effective focal length of the first lens, and D1s is the outer diameter of the object side surface of the first spacer element. By controlling the above conditions, the imaging effect of the optical imaging lens can be effectively optimized, the outer diameter of the object side surface of the first spacer element can be restricted, and the abutment space between the first lens and the second lens can be ensured, which is beneficial to improving the assembly stability of the optical imaging lens.

[0083] In an exemplary embodiment, the optical imaging lens satisfies: 0.60 < (CT2 - CT1) / EP12 < 1.40, where CT1 is the central thickness of the first lens on the first optical axis, CT2 is the central thickness of the second lens on the first optical axis, and EP12 is the distance between the first spacer element and the second spacer element along the first optical axis. By controlling the above conditions, the edge shapes and edge spacings of the first lens and the second lens can be effectively controlled, which is beneficial to improving the stability of lens assembly and the consistency of mass production, and is beneficial to improving the yield of finished products.

[0084] In an exemplary embodiment, the optical imaging lens satisfies: 1.09 < f2 / d2s < 2.30 and 1.41 < D1m / R3 < 1.90, where f2 is the effective focal length of the second lens, d2s is the inner diameter of the object side surface of the second spacer element, D1m is the outer diameter of the image side surface of the first spacer element, and R3 is the radius of curvature of the object side surface of the second lens. By controlling the ratio of the effective focal length of the second lens to the inner diameter of the object side surface of the second spacer element within the above range, the light aperture entering the third and fourth lenses can be within a relatively small range; by controlling the ratio of the outer diameter of the image side surface of the first spacer element to the radius of curvature of the object side surface of the second lens within a relatively small range, the smaller radius of curvature results in a smaller aperture of the second lens and a smaller outer diameter of the first spacer element, ensuring miniaturization of the aperture of the optical imaging lens.

[0085] In an exemplary embodiment, the optical imaging lens satisfies: 4.50 < CT2 / CT3 < 5.40 and -2.00 < f3 / d2m < -1.25, where CT2 is the central thickness of the second lens on the first optical axis, CT3 is the central thickness of the third lens on the first optical axis, f3 is the effective focal length of the third lens, and d2m is the inner diameter of the image side surface of the second spacer element. By restricting the ratio of the central thickness of the second lens on the first optical axis to the central thickness of the third lens on the first optical axis within a certain range, good processability can be ensured while effectively restricting the axial distance between the second and third lenses on the first optical axis; by restricting the effective focal length of the third lens to the inner diameter of the image side surface of the second spacer element, stray light outside the effective optical path can be effectively blocked, improving the imaging quality.

[0086] In an exemplary embodiment, the optical imaging lens satisfies: 1.20 < d0s / d0m < 2.00, where d0s is the inner diameter of the object side end face of the lens barrel, and d0m is the inner diameter of the image side end face of the lens barrel. By controlling the above conditions, the uniformity of the overall thickness of the lens barrel is effectively ensured, which is beneficial for molding. At the same time, in the miniaturization design, the overall assembly stability of the optical imaging lens is effectively ensured.

[0087] In an exemplary embodiment, the optical imaging lens satisfies: 2.80 < f / L < 3.30, where f is the total effective focal length of the optical imaging lens, and L is the maximum length of the lens barrel along the first optical axis. By adjusting the total effective focal length of the optical imaging lens, the field curvature and distortion of the optical imaging lens can be improved. On the premise of ensuring performance, the maximum length of the lens barrel along the first optical axis is restricted by the above conditional formula to achieve miniaturization of the optical imaging lens.

[0088] In an exemplary embodiment, the spacer group further includes a third auxiliary spacer element, which is placed on the image side of the third spacer element and in contact with the image side of the third spacer element, thereby improving the stability of the lens mounting.

[0089] In embodiments of this application, at least one of the surfaces of the second to fourth lenses is an aspherical surface. An aspherical lens is characterized by a continuously changing curvature from its center to its periphery. Unlike a spherical lens, which has a constant curvature from its center to its periphery, an aspherical lens has superior curvature radius characteristics, offering advantages in improving distortion and astigmatism. By employing an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality.

[0090] Those skilled in the art will understand that, without departing from the technical solutions claimed in this application, the number of lenses and spacers constituting the optical imaging lens can be changed to obtain the various results and advantages described in this specification.

[0091] The following describes in further detail, with reference to the accompanying drawings, specific embodiments of the optical imaging lens applicable to the above-described embodiments.

[0092] Example 1

[0093] The following is for reference Figure 2 This application describes the optical imaging lens of Embodiment 1. Figure 2 As shown, the optical imaging lens includes an imaging lens group, a prism T, and an imaging surface IMA. The imaging lens group and the imaging surface IMA are located on the same side of the prism T and are spaced apart from each other.

[0094] Figure 3 A partial structural schematic diagram of the optical imaging lens of Embodiment 1 of this application is shown. Figure 3 The structure of the imaging lens group in the optical imaging lens is shown, but the structure of the prism T and the imaging plane IMA is not shown.

[0095] like Figure 3 As shown, the imaging lens group includes a lens barrel, a four-element lens group disposed within the lens barrel, and a spacer element group. The four-element lens group includes, in sequence along the first optical axis 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. An aperture stop STO (not shown) is disposed on the image side of the fourth lens E4.

[0096] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave.

[0097] The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, and a second auxiliary spacer P2b. The first spacer P1 is positioned between a first lens E1 and a second lens E2, with its object-side surface at least partially contacting the image-side surface S2 of the first lens E1. The second spacer P2 is positioned between the second lens E2 and the third lens E3, with its object-side surface at least partially contacting the image-side surface S4 of the second lens E2. The third spacer P3 is positioned between the third lens E3 and the fourth lens E4, with its object-side surface at least partially contacting the image-side surface S6 of the third lens E3. The second auxiliary spacer P2b is positioned on the image side of the second spacer P2, with its object-side surface at least partially contacting the image-side surface of the second spacer P2.

[0098] In the example, refer to Figure 2 The prism T and the imaging plane IMA may also include a filter P disposed on the second optical axis. The filter P has an object side surface S9 (not shown) and an image side surface S10 (not shown).

[0099] Light from the object passes sequentially through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and after multiple reflections (e.g., 3 times) inside the prism T, it passes through the filter P and is imaged on the imaging plane IMA.

[0100] Table 1 shows the basic parameters of the optical imaging lens of Example 1, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0101] Table 1

[0102]

[0103]

[0104] In this embodiment, the object-side surface and image-side surface of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces, and the surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0105]

[0106] Where x is the distance vector from the vertex of the aspherical surface at a height of h along the first optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical surfaces S3 to S8 in Example 1.

[0107] Table 2

[0108]

[0109] Example 2

[0110] The following is for reference Figure 2 This application describes the optical imaging lens of Embodiment 2. Figure 2 As shown, the optical imaging lens includes an imaging lens group, a prism T, and an imaging surface IMA. The imaging lens group and the imaging surface IMA are located on the same side of the prism T and are spaced apart from each other.

[0111] Figure 4 A partial structural schematic diagram of the optical imaging lens of Embodiment 2 of this application is shown. Figure 4 The structure of the imaging lens group in the optical imaging lens is shown, but the structure of the prism T and the imaging plane IMA is not shown.

[0112] like Figure 4 As shown, the imaging lens group includes a lens barrel, a four-element lens group disposed within the lens barrel, and a spacer element group. The four-element lens group includes, in sequence along the first optical axis 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. An aperture stop STO (not shown) is disposed on the image side of the fourth lens E4.

[0113] The spacer element group includes a first spacer element P1, a second spacer element P2, a third spacer element P3, and a second auxiliary spacer element P2b.

[0114] The four-element lens group of the optical imaging lens in this embodiment has the same structure as the four-element lens group of the optical imaging lens in Embodiment 1. Its basic parameters are detailed in Tables 1 and 2, and will not be repeated here.

[0115] The difference between this embodiment and Embodiment 1 is that at least some of the components in the lens barrel and spacer element group have different structural dimensions.

[0116] Example 3

[0117] The following is for reference Figure 2 The optical imaging lens of Embodiment 3 of this application is described. For example... Figure 2As shown, the optical imaging lens includes an imaging lens group, a prism T, and an imaging surface IMA. The imaging lens group and the imaging surface IMA are located on the same side of the prism T and are spaced apart from each other.

[0118] Figure 5 A partial structural schematic diagram of the optical imaging lens of Embodiment 3 of this application is shown. Figure 5 The structure of the imaging lens group in the optical imaging lens is shown, but the structure of the prism T and the imaging plane IMA is not shown.

[0119] like Figure 5 As shown, the imaging lens group includes a lens barrel, a four-element lens group disposed within the lens barrel, and a spacer element group. The four-element lens group includes, in sequence along the first optical axis 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. An aperture stop STO (not shown) is disposed on the image side of the fourth lens E4.

[0120] The spacer element group includes a first spacer element P1, a second spacer element P2, a third spacer element P3, and a second auxiliary spacer element P2b.

[0121] The four-element lens group of the optical imaging lens in this embodiment has the same structure as the four-element lens group of the optical imaging lens in Embodiment 1. Its basic parameters are detailed in Tables 1 and 2, and will not be repeated here.

[0122] The difference between this embodiment and Embodiment 1 is that at least some of the components in the lens barrel and spacer element group have different structural dimensions.

[0123] Figure 6 (A1) shows the astigmatism curves of the optical imaging lenses of Embodiments 1, 2 and 3, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 6 (B1) shows the distortion curves of the optical imaging lenses of Examples 1, 2 and 3, which represent the distortion magnitude values ​​corresponding to different field of view angles. Figure 6 (C1) shows the relative illuminance curves of the optical imaging lenses of Examples 1, 2, and 3, which represent the luminous flux received per unit area. According to Figure 6 It can be seen that the optical imaging lenses provided in Embodiments 1, 2 and 3 can achieve good imaging quality.

[0124] Example 4

[0125] The following is for reference Figure 2 The optical imaging lens of Embodiment 4 of this application is described. For example... Figure 2 As shown, the optical imaging lens includes an imaging lens group, a prism T, and an imaging surface IMA. The imaging lens group and the imaging surface IMA are located on the same side of the prism T and are spaced apart from each other.

[0126] Figure 7 A partial structural schematic diagram of the optical imaging lens of Embodiment 4 of this application is shown. Figure 7 The structure of the imaging lens group in the optical imaging lens is shown, but the structure of the prism T and the imaging plane IMA is not shown.

[0127] like Figure 7 As shown, the imaging lens group includes a lens barrel, a four-element lens group disposed within the lens barrel, and a spacer element group. The four-element lens group includes, in sequence along the first optical axis 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. An aperture stop STO (not shown) is disposed on the image side of the fourth lens E4.

[0128] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave.

[0129] The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, and a second auxiliary spacer P2b. The first spacer P1 is positioned between a first lens E1 and a second lens E2, with its object-side surface at least partially contacting the image-side surface S2 of the first lens E1. The second spacer P2 is positioned between the second lens E2 and the third lens E3, with its object-side surface at least partially contacting the image-side surface S4 of the second lens E2. The third spacer P3 is positioned between the third lens E3 and the fourth lens E4, with its object-side surface at least partially contacting the image-side surface S6 of the third lens E3. The second auxiliary spacer P2b is positioned on the image side of the second spacer P2, with its object-side surface at least partially contacting the image-side surface of the second spacer P2.

[0130] In the example, refer to Figure 2 The prism T and the imaging plane IMA may also include a filter P disposed on the second optical axis. The filter P has an object side surface S9 (not shown) and an image side surface S10 (not shown).

[0131] Light from the object passes sequentially through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and after multiple reflections (e.g., 3 times) inside the prism T, it passes through the filter P and is imaged on the imaging plane IMA.

[0132] Table 3 shows the basic parameters of the optical imaging lens of Example 4, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0133] Table 3

[0134]

[0135] In this embodiment, the object-side surface and image-side surface of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces. Table 4 shows the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspherical surface S3 to S8 in Embodiment 4.

[0136] Table 4

[0137]

[0138]

[0139] Example 5

[0140] The following is for reference Figure 2 The optical imaging lens of Embodiment 5 of this application is described. For example... Figure 2 As shown, the optical imaging lens includes an imaging lens group, a prism T, and an imaging surface IMA. The imaging lens group and the imaging surface IMA are located on the same side of the prism T and are spaced apart from each other.

[0141] Figure 8 A partial structural schematic diagram of the optical imaging lens of Embodiment 5 of this application is shown. Figure 8 The structure of the imaging lens group in the optical imaging lens is shown, but the structure of the prism T and the imaging plane IMA is not shown.

[0142] like Figure 8 As shown, the imaging lens group includes a lens barrel, a four-element lens group disposed within the lens barrel, and a spacer element group. The four-element lens group includes, in sequence along the first optical axis 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. An aperture stop STO (not shown) is disposed on the image side of the fourth lens E4.

[0143] The spacer element group includes a first spacer element P1, a second spacer element P2, a third spacer element P3, and a second auxiliary spacer element P2b.

[0144] The four-element lens group of the optical imaging lens in this embodiment has the same structure as the four-element lens group of the optical imaging lens in embodiment 4. Its basic parameters are detailed in Tables 3 and 4, and will not be repeated here.

[0145] The difference between this embodiment and embodiment 4 is that at least some of the components in the lens barrel and spacer element group have different structural dimensions.

[0146] Example 6

[0147] The following is for referenceFigure 2 The optical imaging lens of Embodiment 6 of this application is described. For example... Figure 2 As shown, the optical imaging lens includes an imaging lens group, a prism T, and an imaging surface IMA. The imaging lens group and the imaging surface IMA are located on the same side of the prism T and are spaced apart from each other.

[0148] Figure 9 A partial structural schematic diagram of the optical imaging lens of Embodiment 6 of this application is shown. Figure 9 The structure of the imaging lens group in the optical imaging lens is shown, but the structure of the prism T and the imaging plane IMA is not shown.

[0149] like Figure 9 As shown, the imaging lens group includes a lens barrel, a four-element lens group disposed within the lens barrel, and a spacer element group. The four-element lens group includes, in sequence along the first optical axis 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. An aperture stop STO (not shown) is disposed on the image side of the fourth lens E4.

[0150] The spacer element group includes a first spacer element P1, a second spacer element P2, a third spacer element P3, and a second auxiliary spacer element P2b.

[0151] The four-element lens group of the optical imaging lens in this embodiment has the same structure as the four-element lens group of the optical imaging lens in embodiment 4. Its basic parameters are detailed in Tables 3 and 4, and will not be repeated here.

[0152] The difference between this embodiment and embodiment 4 is that at least some of the components in the lens barrel and spacer element group have different structural dimensions.

[0153] Figure 10 (A2) shows the astigmatism curves of the optical imaging lenses of Examples 1, 2 and 3, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 10 (B2) shows the distortion curves of the optical imaging lenses of Examples 1, 2 and 3, which represent the distortion magnitude values ​​corresponding to different field of view angles. Figure 10 (C2) shows the relative illuminance curves of the optical imaging lenses of Examples 1, 2, and 3, which represent the luminous flux received per unit area. According to Figure 10 It can be seen that the optical imaging lenses provided in Embodiments 1, 2 and 3 can achieve good imaging quality.

[0154] Example 7

[0155] The following is for reference Figure 2 The optical imaging lens of Embodiment 7 of this application is described. For example... Figure 2As shown, the optical imaging lens includes an imaging lens group, a prism T, and an imaging surface IMA. The imaging lens group and the imaging surface IMA are located on the same side of the prism T and are spaced apart from each other.

[0156] Figure 11 A partial structural schematic diagram of the optical imaging lens of Embodiment 7 of this application is shown. Figure 11 The structure of the imaging lens group in the optical imaging lens is shown, but the structure of the prism T and the imaging plane IMA is not shown.

[0157] like Figure 11 As shown, the imaging lens group includes a lens barrel, a four-element lens group disposed within the lens barrel, and a spacer element group. The four-element lens group includes, in sequence along the first optical axis 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. An aperture stop STO (not shown) is disposed on the image side of the fourth lens E4.

[0158] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave.

[0159] The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, and a third auxiliary spacer P3b. The first spacer P1 is positioned between a first lens E1 and a second lens E2, with its object-side surface at least partially contacting the image-side surface S2 of the first lens E1. The second spacer P2 is positioned between the second lens E2 and the third lens E3, with its object-side surface at least partially contacting the image-side surface S4 of the second lens E2. The third spacer P3 is positioned between the third lens E3 and the fourth lens E4, with its object-side surface at least partially contacting the image-side surface S6 of the third lens E3. The third auxiliary spacer P3b is positioned on the image side of the third spacer P3, with its object-side surface at least partially contacting the image-side surface of the third spacer P3.

[0160] In the example, refer to Figure 2 The prism T and the imaging plane IMA may also include a filter P disposed on the second optical axis. The filter P has an object side surface S9 (not shown) and an image side surface S10 (not shown).

[0161] Light from the object passes sequentially through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and after multiple reflections (e.g., 3 times) inside the prism T, it passes through the filter P and is imaged on the imaging plane IMA.

[0162] Table 5 shows the basic parameters of the optical imaging lens of Example 7, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0163] Table 5

[0164]

[0165]

[0166] In this embodiment, the object-side surface and image-side surface of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces. Table 6 shows the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspherical surface S3 to S8 in Embodiment 7.

[0167] Table 6

[0168]

[0169] Example 8

[0170] The following is for reference Figure 2 The optical imaging lens of Embodiment 8 of this application is described. For example... Figure 2 As shown, the optical imaging lens includes an imaging lens group, a prism T, and an imaging surface IMA. The imaging lens group and the imaging surface IMA are located on the same side of the prism T and are spaced apart from each other.

[0171] Figure 12 A partial structural schematic diagram of the optical imaging lens of Embodiment 8 of this application is shown. Figure 12 The structure of the imaging lens group in the optical imaging lens is shown, but the structure of the prism T and the imaging plane IMA is not shown.

[0172] like Figure 12 As shown, the imaging lens group includes a lens barrel, a four-element lens group disposed within the lens barrel, and a spacer element group. The four-element lens group includes, in sequence along the first optical axis 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. An aperture stop STO (not shown) is disposed on the image side of the fourth lens E4.

[0173] The spacer element group includes a first spacer element P1, a second spacer element P2, a third spacer element P3, and a third auxiliary spacer element P3b.

[0174] The four-element lens group of the optical imaging lens in this embodiment has the same structure as the four-element lens group of the optical imaging lens in embodiment 7. Its basic parameters are detailed in Tables 5 and 6, and will not be repeated here.

[0175] The difference between this embodiment and embodiment 7 is that at least some of the components in the lens barrel and spacer element group have different structural dimensions.

[0176] Example 9

[0177] The following is for reference Figure 2 The optical imaging lens of Embodiment 9 of this application is described. For example... Figure 2 As shown, the optical imaging lens includes an imaging lens group, a prism T, and an imaging surface IMA. The imaging lens group and the imaging surface IMA are located on the same side of the prism T and are spaced apart from each other.

[0178] Figure 13 A partial structural schematic diagram of the optical imaging lens of Embodiment 9 of this application is shown. Figure 13 The structure of the imaging lens group in the optical imaging lens is shown, but the structure of the prism T and the imaging plane IMA is not shown.

[0179] like Figure 13 As shown, the imaging lens group includes a lens barrel, a four-element lens group disposed within the lens barrel, and a spacer element group. The four-element lens group includes, in sequence along the first optical axis 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. An aperture stop STO (not shown) is disposed on the image side of the fourth lens E4.

[0180] The spacer element group includes a first spacer element P1, a second spacer element P2, a third spacer element P3, and a third auxiliary spacer element P3b.

[0181] The four-element lens group of the optical imaging lens in this embodiment has the same structure as the four-element lens group of the optical imaging lens in embodiment 7. Its basic parameters are detailed in Tables 5 and 6, and will not be repeated here.

[0182] The difference between this embodiment and embodiment 7 is that at least some of the components in the lens barrel and spacer element group have different structural dimensions.

[0183] Figure 14 (A3) shows the astigmatism curves of the optical imaging lenses of Examples 1, 2 and 3, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 14 (B3) shows the distortion curves of the optical imaging lenses of Examples 1, 2 and 3, which represent the distortion magnitude values ​​corresponding to different field of view angles. Figure 14 (C3) shows the relative illuminance curves of the optical imaging lenses of Examples 1, 2, and 3, which represent the luminous flux received per unit area. According to Figure 14 It can be seen that the optical imaging lenses provided in Embodiments 1, 2 and 3 can achieve good imaging quality.

[0184] Table 7 provides the parameter values ​​for f, f1, f2, f3, f4, SAG32, and SAG41 for each of Examples 1 to 9. All parameters listed in Table 7 are in millimeters (mm).

[0185] Table 7

[0186]

[0187] Table 8 provides the parameter values ​​for at least some of the elements in the lens barrel and spacer element group of each embodiment from Embodiment 1 to Embodiment 9. Some of these parameters can be determined according to... Figure 1 The measurements were obtained using the annotation method shown, and the units of the parameters listed in Table 8 are all millimeters (mm).

[0188] Table 8

[0189]

[0190] In summary, the optical imaging lenses in Examples 1 to 9 satisfy the relationships shown in Table 9.

[0191] Table 9

[0192]

[0193] This application also provides an electronic device equipped with the optical imaging lens described above. The electronic device can be a wearable device such as a smartwatch or smart glasses, a standalone imaging device such as a range detector, a standalone imaging device such as a vehicle-mounted camera, a mobile electronic device such as a mobile phone or tablet, an imaging module integrated into a range detector, or an imaging module integrated into a driver assistance system, etc.

[0194] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An optical imaging lens, characterized in that, The optical imaging lens comprises an imaging lens group, a prism and an imaging surface, the imaging lens group and the imaging surface are located on the same side of the prism; wherein, The imaging lens group comprises: A lens group is composed of a first lens with negative refractive power, a second lens with positive refractive power, a third lens with negative refractive power and a fourth lens with positive refractive power arranged in order along a first optical axis from the object side to the image side, wherein the central thickness of the second lens on the first optical axis is greater than the central thickness of any one lens in the imaging lens group except the second lens on the first optical axis; A spacer element group comprises a first spacer element and a second spacer element, the first spacer element is arranged between the first lens and the second lens and in contact with the image side surface of the first lens, and the second spacer element is arranged between the second lens and the third lens and in contact with the image side surface of the second lens; and A lens barrel containing the lens group and the spacer element group; The optical imaging lens satisfies: 6.74 < EP12 / T12 < 12.80 and 31.30 < CT2 / (T23+CP2) < 40.15; Wherein, EP12 is the distance between the first spacer element and the second spacer element along the first optical axis direction, T12 is the interval distance between the first lens and the second lens on the first optical axis, CT2 is the central thickness of the second lens on the first optical axis, T23 is the interval distance between the second lens and the third lens on the first optical axis, and CP2 is the maximum thickness of the second spacer element. 2.The optical imaging lens according to claim 1, wherein, The spacer element group further comprises a third spacer element, the third spacer element is arranged between the third lens and the fourth lens and in contact with the image side surface of the third lens; The optical imaging lens satisfies: 0.92 < R5 / D2m < 8.80 and 1.28 < d3s / R6 < 1.59, wherein R5 is the curvature radius of the object side surface of the third lens, R6 is the curvature radius of the image side surface of the third lens, D2m is the outer diameter of the image side surface of the second spacer element, and d3s is the inner diameter of the object side surface of the third spacer element. 3.The optical imaging lens according to claim 1, wherein, The spacer element group further comprises a third spacer element, the third spacer element is arranged between the third lens and the fourth lens and in contact with the image side surface of the third lens; The optical imaging lens satisfies: 2.40 < EP23 / CT3 < 3.17, wherein EP23 is the distance between the second spacer element and the third spacer element along the first optical axis direction, and CT3 is the central thickness of the third lens on the first optical axis. 4.The optical imaging lens according to claim 1, wherein, The spacer element group further comprises a third spacer element, the third spacer element is arranged between the third lens and the fourth lens and in contact with the image side surface of the third lens; The optical imaging lens satisfies: 0.65 < SAG41 / (CT4+CP3) < 1.47, wherein SAG41 is an on-axis distance between an intersection of the first optical axis and an object side surface of the fourth lens and an effective radius vertex of the object side surface of the fourth lens, CT4 is a center thickness of the fourth lens on the first optical axis, and CP3 is a maximum thickness of the third spacer element.

5. The optical imaging lens according to claim 1, characterized in that, The spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with an image side surface of the third lens. The optical imaging lens satisfies: -13.25 < f4 / f3 < -1.26 and 1.10 < (CP3+CT4) / CT3 < 2.69, wherein f3 is an effective focal length of the third lens, f4 is an effective focal length of the fourth lens, CP3 is a maximum thickness of the third spacer element, CT3 is a center thickness of the third lens on the first optical axis, and CT4 is a center thickness of the fourth lens on the first optical axis. 6.The optical imaging lens according to claim 1, wherein, The spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with an image side surface of the third lens. The optical imaging lens satisfies: 1.72 < EP23 / SAG32 < 2.90, wherein EP23 is a distance between the second spacer element and the third spacer element along the first optical axis direction, and SAG32 is an on-axis distance between an intersection of the first optical axis and an image side surface of the third lens and an effective radius vertex of the image side surface of the third lens. 7.The optical imaging lens according to claim 1, wherein, The spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with an image side surface of the third lens. The optical imaging lens satisfies: 0.72 < R7 / R8 < 1.10 and 1.51 < d3m / R7 < 2.40, wherein R7 is a curvature radius of an object side surface of the fourth lens, R8 is a curvature radius of an image side surface of the fourth lens, and d3m is an inner diameter of an image side surface of the third spacer element. 8.The optical imaging lens according to claim 1, wherein, The spacer element group further includes a second auxiliary spacer element disposed on an image side of the second spacer element and in contact with an image side surface of the second spacer element. The optical imaging lens satisfies: 6.50 < (CP2+CP2b) / T23 < 11.75, wherein CP2b is a maximum thickness of the second auxiliary spacer element. 9.The optical imaging lens according to claim 1, wherein, The spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with an image side surface of the third lens. A maximum outer diameter of the first spacer element is greater than a maximum outer diameter of the second spacer element, and the maximum outer diameter of the second spacer element is greater than a maximum outer diameter of the third spacer element. A minimum inner diameter of the second spacer element is smaller than a minimum inner diameter of any one of the spacer elements in the spacer element group except the second spacer element. 10.The optical imaging lens according to any one of claims 1-9, wherein, The optical imaging lens satisfies -24.50 < f1 / D1s < -20.50, where f1 is an effective focal length of the first lens, and D1s is an outer diameter of an object side surface of the first spacer element.

11. The optical imaging lens according to any one of claims 1-9, wherein, The optical imaging lens satisfies 0.60 < (CT2-CT1) / EP12 < 1.40, where CT1 is a central thickness of the first lens on the first optical axis.

12. The optical imaging lens according to any one of claims 1-9, wherein, The optical imaging lens satisfies 1.09 < f2 / d2s < 2.30 and 1.41 < D1m / R3 < 1.90, where f2 is an effective focal length of the second lens, d2s is an inner diameter of an object side surface of the second spacer element, D1m is an outer diameter of an image side surface of the first spacer element, and R3 is a curvature radius of an object side surface of the second lens.

13. The optical imaging lens according to any one of claims 1-9, wherein, The optical imaging lens satisfies 4.50 < CT2 / CT3 < 5.40 and -2.00 < f3 / d2m < -1.25, where CT3 is a central thickness of the third lens on the first optical axis, f3 is an effective focal length of the third lens, and d2m is an inner diameter of an image side surface of the second spacer element.

14. The optical imaging lens according to any of claims 1-9, wherein, The optical imaging lens satisfies 1.20 < d0s / d0m < 2.00, where d0s is an inner diameter of an object side end surface of the lens barrel, and d0m is an inner diameter of an image side end surface of the lens barrel.

15. The optical imaging lens according to any one of claims 1-9, wherein, The optical imaging lens satisfies 2.80 < f / L < 3.30, where f is a total effective focal length of the optical imaging lens, and L is a maximum length of the lens barrel along the first optical axis.

16. The optical imaging lens according to any one of claims 1-9, wherein: an object side surface of the first lens is convex, and an image side surface of the first lens is concave; an object side surface of the second lens is convex; an object side surface of the third lens is convex, and an image side surface of the third lens is concave; an object side surface of the fourth lens is convex, and an image side surface of the fourth lens is concave.

Images