Optical imaging lens

Abstract

The invention discloses an optical imaging lens, which comprises an imaging lens group, the imaging lens group comprises a lens group and a spacing element group, and the lens group is composed of a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged from an object side to an image side along a first optical axis; the spacing element group comprises a first spacing element and a second spacing element; the optical imaging lens satisfies the following conditions: 6.74 lt; eP12 / T12lt; 12.80 and 31.30 lt, 12.80 and 31.30 CT2 / (T23 + CP2) lt; eP12 is the distance between the first spacing element and the second spacing element in the first optical axis direction, T12 is the spacing distance between 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 spacing distance between the second lens and the third lens on the first optical axis, and CP2 is the maximum thickness of the second spacing 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 the optical imaging lens is a telephoto lens. The larger the total effective focal length of the optical imaging lens, the clearer the distant objects photographed by the optical imaging lens. However, the larger the total effective focal length of the optical imaging lens, the greater the optical path required by the optical imaging lens. Therefore, in order to achieve the telephoto characteristics of the 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, the miniaturization of optical imaging lenses is an important development trend. However, in the prior art, while achieving the miniaturization of optical imaging lenses, it often affects the imaging quality or assembly stability of optical imaging lenses, 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 is in contact with the image side surface of the first lens. The second spacer element is placed 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.

[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 point 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 point 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 smaller 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 have appearance problems due to uneven thickness ratio, and then the assembly becomes unstable. 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 a distance between the second lens and the third lens, and improve the assembly stability. 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] 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 partial schematic diagram showing the structure of the optical imaging lens of Embodiment 1 of the present application;

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

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

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

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

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

[0030] Fig. 9 A partial structural schematic diagram of an optical imaging lens according to Embodiment 6 of the present application is shown;

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

[0032] Fig.11 A partial structural schematic diagram of an optical imaging lens according to Embodiment 7 of the present application is shown;

[0033] Fig.12 A partial structural schematic diagram of an optical imaging lens according to Example 8 of the present application is shown;

[0034] Fig.13 A partial structural schematic diagram of an optical imaging lens according to Example 9 of the present application is shown;

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

[0036] Fig.15 The modulation transfer function (MTF) curve of the optical imaging lens of the present application is shown when EP12 / T12=9.01 and CT2 / (T23+CP2)=20 are satisfied;

[0037] Fig.16 The MTF curve of the optical imaging lens of the present application is shown when EP12 / T12=9.01 and CT2 / (T23+CP2)=55 are satisfied;

[0038] Fig.17 The MTF curve of the optical imaging lens of the present application is shown when EP12 / T12=9.01 and CT2 / (T23+CP2)=32.83 are satisfied. DETAILED DESCRIPTION

[0039] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and do not limit the scope of the present application in any way. Throughout the specification, the same figure numerals refer to the same elements.

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

[0041] In the 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 shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0042] In this article, if the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial 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 of the lens, and the surface closest to the image side is the image side of the lens.

[0043] It should also be understood that the terms "including" 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. In addition, when describing the embodiments of the present application, the term "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

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

[0045] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be noted that, for those of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can also be made, which all belong to the protection scope of the present application, for example, the elements in the various embodiments of the present application can be arbitrarily combined.

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

[0047] Figure 1 The following is a schematic diagram showing some parameters of an optical imaging lens of the present application, so as to facilitate a better understanding of the present 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 face of the first spacer element, d2s is the inner diameter of the object side face of the second spacer element, d3s is the inner diameter of the object side face of the third spacer element, d3m is the inner diameter of the image side face of the third spacer element, d2m is the inner diameter of the image side face 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 face of the second spacer element, D1m is the outer diameter of the image side face 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 The schematic diagram of the structure of an optical imaging lens of the present application is shown as an example. Figure 2 As shown, the optical imaging lens provided by the present application may include 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.

[0049] In an exemplary embodiment, 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 reflective surface (eg, 103 or 104), wherein the at least one reflective surface (eg, 103 or 104) is used to connect the first surface 101 and the second surface 102.

[0050] In an exemplary embodiment, reference Figure 2The imaging lens group and the imaging surface IMA are located on a side of the prism T close to the second surface 102 thereof 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 prism T is arranged along the first optical axis with the imaging lens group, and another portion of the prism T is arranged along the second optical axis with the imaging surface IMA, and the first optical axis is parallel to the second optical axis.

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

[0052] In an exemplary embodiment, the light 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 be reflected multiple times inside the prism. The light after multiple reflections can then be emitted along the second optical axis through the exit area of ​​the second surface of the prism.

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

[0054] In an exemplary embodiment, the light 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 be redirected to the reflection area of ​​the second surface by the first reflection surface of the prism for the first time by total reflection, and then be redirected to the second reflection surface of the prism by the reflection area of ​​the second surface by total reflection for the second time, and be redirected to the exit area of ​​the second surface by the second reflection surface of the prism for the third time, and exit along the second optical axis through the exit area of ​​the second surface of the prism.

[0055] It should be noted that the number of times the light is reflected inside the prism is 3 times for example only, and may also be 5 times, 7 times, etc. The number of times the light is reflected inside the prism is related to the aperture size of the first surface and the second surface of the prism and the distance between the first surface and the second surface of the prism. The structure of the prism can be adjusted as needed to adjust the number of reflections, and this application does not impose any specific restrictions on this.

[0056] The optical imaging lens provided in the present application can make light reflect multiple times inside the prism by setting a prism, thereby achieving the telephoto characteristic of the optical imaging lens while satisfying the miniaturization of the optical imaging lens.

[0057] In an exemplary embodiment, the imaging lens group includes a lens group, and the lens group is composed of a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object side to the image side along the first optical axis. Each lens has an effective diameter area through which light can pass and a non-effective diameter area surrounding the effective diameter area through which light cannot pass. Among the first lens to the fourth lens, any two adjacent lenses may have a spacing distance on the first optical axis, and the spacing distance may be an air spacing.

[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 refractive power. The object side surface of the second lens is convex, and the image side surface is convex or concave. The second lens with positive refractive power has the function of converging light.

[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 refractive 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, which is disposed between the lenses and located in the non-effective diameter region of the lenses. It should be understood that the present application does not specifically limit the number of spacer elements, and at least one spacer element is disposed between any two adjacent lenses, and the entire optical imaging lens may also include any number of spacer elements. The spacer element helps the optical imaging lens intercept excess refractive and reflective light paths, reduce stray light and ghost images, and improve imaging quality.

[0063] In an exemplary embodiment, the optical imaging lens further includes a lens barrel. The lens group and the spacer element group are disposed in 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 farthest 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 for limiting the light beam, which is conducive to converging the light entering the optical lens, reducing the maximum aperture of the optical lens, and reducing the assembly sensitivity of the system to further improve the imaging quality of the optical lens. It should be noted that the aperture can be set between or on one side of any lens according to actual needs. Exemplarily, the aperture is set 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 emitted from the exit region of the second surface 102 of the prism T is 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 one of the lenses other than 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 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, pushing-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 occurrence of stray light phenomenon, and ensure the imaging quality of the optical imaging lens.

[0067] Fig.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] Fig.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] Fig.17The MTF curve of the optical imaging lens of the present application is shown when EP12 / T12=9.01 and CT2 / (T23+CP2)=32.83 are satisfied.

[0070] Fig.15 The optical imaging lens in satisfies the limited range of the conditional formula EP12 / T12 in this application, and satisfies the situation that the center thickness of the second lens on the optical axis is the largest. However, at this time, it is easy to cause appearance problems due to uneven thickness ratio, and then cause unstable assembly. However, since the conditional formula CT2 / (T23+CP2) is less than the limited range of this application, the center thickness of the second lens is too thin, which is easy to cause problems of weak lens strength, push-off force and temperature term reliability, which is not conducive to the molding of the second lens. It is also easy to cause appearance problems due to uneven thickness ratio of the second lens, and then produce stray light phenomenon, affecting the imaging quality of the optical imaging lens. Fig.15 It can be seen that the MTF curve is relatively scattered.

[0071] Fig.16 The optical imaging lens in satisfies the limited range of the conditional formula EP12 / T12 in this application, and satisfies the situation that the center thickness of the second lens on the optical axis is the largest. However, it is easy to cause appearance problems due to uneven thickness ratio, and then cause assembly instability. However, since the conditional formula CT2 / (T23+CP2) is greater than the limited range of this application, the distance between the second lens and the third lens is too small, causing assembly collision problems, poor assembly stability, and affecting the imaging quality of the optical imaging lens. Fig.16 It can be seen that the MTF curve is relatively scattered.

[0072] Fig.17 The optical imaging lens in satisfies the limited range of the conditional formula EP12 / T12 in the present application, and satisfies the situation that the center thickness of the second lens on the optical axis is the largest. However, at this time, it is easy to cause appearance problems due to uneven thickness ratio, and then cause assembly instability. By controlling the conditional formula CT2 / (T23+CP2) to meet the limited range of the present application, the distance between the second lens and the third lens can be adjusted to avoid assembly collision problems caused by the distance between the second lens and the third lens being too small, thereby improving assembly stability. It can also avoid problems such as weak lens strength, push-off force and temperature reliability caused by the center thickness of the second lens being too thin. 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 stray light phenomena, thereby improving the imaging quality of the optical imaging lens. Fig.17 It can be seen that the MTF curve is 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 shape optical sensitivity can be reduced, which is beneficial to surface shape 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 light rays. 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 disposed 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: -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 there is a large difference between the effective focal lengths of the third lens and the fourth lens, there are also significant differences in the shapes of the third lens and the fourth lens. 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 disposed 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: 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 vertex of the effective radius 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 vertex of the effective radius 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 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 disposed 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: 0.72 < 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 to the curvature radius of the image side surface of the fourth lens within a small range ensures that the left and right sides of the fourth lens bend in the same direction with small differences, 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 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 and 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 spacer element 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 lens and the fourth lens 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 constraining 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 constraining the axial distance between the second lens and the third lens on the first optical axis; by constraining the effective focal length of the third lens and 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 constrained by the above conditional formula to achieve miniaturization of the optical imaging lens.

[0088] In an exemplary embodiment, the spacer element group further includes a third auxiliary spacer element, which is disposed on the image side of the third spacer element and in contact with the image side surface of the third spacer element, and can improve the stability of the lens installation.

[0089] In an embodiment of the present application, at least one of the surfaces of each lens in the second lens to the fourth lens is an aspherical surface. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After adopting an aspherical lens, the aberration occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality.

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

[0091] Specific embodiments of the optical imaging lens applicable to the above-mentioned embodiments are further described below with reference to the accompanying drawings.

[0092] Example 1

[0093] The following references Figure 2 The optical imaging lens of Example 1 of the present application is described. 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 Example 1 of the present application is shown. Figure 3 The structure of the imaging lens group in the optical imaging lens is shown in FIG, but the structure of the prism T and the imaging surface IMA are not shown.

[0095] like Figure 3 As shown, the imaging lens group includes a lens barrel, a four-piece lens group arranged in the lens barrel, and a spacer element group. The four-piece lens group includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 in order from the object side to the image side along the first optical axis. A stop STO (not shown) is arranged on the image side of the fourth lens E4.

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

[0097] 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. The first spacer element P1 is placed between the first lens E1 and the second lens E2, and the object side surface of the first spacer element P1 is at least partially in contact with the image side surface S2 of the first lens E1. The second spacer element P2 is placed between the second lens E2 and the third lens E3, and the object side surface of the second spacer element P2 is at least partially in contact with the image side surface S4 of the second lens E2. The third spacer element P3 is placed between the third lens E3 and the fourth lens E4, and the object side surface of the third spacer element P3 is at least partially in contact with the image side surface S6 of the third lens E3. The second auxiliary spacer element P2b is placed on the image side of the second spacer element P2, and the object side surface of the second auxiliary spacer element P2b is at least partially in contact with the image side surface S6 of the second spacer element P2.

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

[0099] Light from an object passes through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4 in sequence, and after multiple reflections (for example, 3 times) inside the prism T, passes through the filter P and is imaged on the imaging surface IMA.

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

[0101] Table 1

[0102]

[0103]

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

[0105]

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

[0107] Table 2

[0108]

[0109] Example 2

[0110] The following references Figure 2 The optical imaging lens of Example 2 of the present application is described. 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 Example 2 of the present application is shown. Figure 4 The structure of the imaging lens group in the optical imaging lens is shown in FIG, but the structure of the prism T and the imaging surface IMA are not shown.

[0112] like Figure 4 As shown, the imaging lens group includes a lens barrel, a four-piece lens group arranged in the lens barrel, and a spacer element group. The four-piece lens group includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 in order from the object side to the image side along the first optical axis. A stop STO (not shown) is arranged on the image side of the fourth lens E4.

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

[0114] The structure of the four-lens group of the optical imaging lens of this embodiment is the same as that of the four-lens group of the optical imaging lens in Embodiment 1. The basic parameters thereof are detailed in Tables 1 and 2 and will not be described in detail.

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

[0116] Example 3

[0117] The following references Figure 2 The optical imaging lens of Example 3 of the present application is described. 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 Example 3 of the present application is shown. Figure 5 The structure of the imaging lens group in the optical imaging lens is shown in FIG, but the structure of the prism T and the imaging surface IMA are not shown.

[0119] like Figure 5 As shown, the imaging lens group includes a lens barrel, a four-piece lens group arranged in the lens barrel, and a spacer element group. The four-piece lens group includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 in order from the object side to the image side along the first optical axis. A stop STO (not shown) is arranged on the image side of the fourth lens E4.

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

[0121] The structure of the four-lens group of the optical imaging lens of this embodiment is the same as that of the four-lens group of the optical imaging lens in Embodiment 1. The basic parameters thereof are detailed in Tables 1 and 2 and will not be described in detail.

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

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

[0124] Example 4

[0125] The following references Figure 2 The optical imaging lens of Example 4 of the present application is described. 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 an optical imaging lens according to Example 4 of the present application is shown. Figure 7 The structure of the imaging lens group in the optical imaging lens is shown in FIG, but the structure of the prism T and the imaging surface IMA are not shown.

[0127] like Figure 7 As shown, the imaging lens group includes a lens barrel, a four-piece lens group arranged in the lens barrel, and a spacer element group. The four-piece lens group includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 in order from the object side to the image side along the first optical axis. A stop STO (not shown) is arranged on the image side of the fourth lens E4.

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

[0129] 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. The first spacer element P1 is placed between the first lens E1 and the second lens E2, and the object side surface of the first spacer element P1 is at least partially in contact with the image side surface S2 of the first lens E1. The second spacer element P2 is placed between the second lens E2 and the third lens E3, and the object side surface of the second spacer element P2 is at least partially in contact with the image side surface S4 of the second lens E2. The third spacer element P3 is placed between the third lens E3 and the fourth lens E4, and the object side surface of the third spacer element P3 is at least partially in contact with the image side surface S6 of the third lens E3. The second auxiliary spacer element P2b is placed on the image side of the second spacer element P2, and the object side surface of the second auxiliary spacer element P2b is at least partially in contact with the image side surface S6 of the second spacer element P2.

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

[0131] Light from an object passes through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4 in sequence, and after multiple reflections (for example, 3 times) inside the prism T, passes through the filter P and is imaged on the imaging surface IMA.

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

[0133] Table 3

[0134]

[0135] In this embodiment, the object side surface and the image side surface of any lens from the second lens E2 to the fourth lens E4 are both aspherical surfaces. Table 4 shows the high-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 4.

[0136] Table 4

[0137]

[0138]

[0139] Example 5

[0140] The following references Figure 2 The optical imaging lens of Example 5 of the present application is described. 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 Example 5 of the present application is shown. Figure 8 The structure of the imaging lens group in the optical imaging lens is shown in FIG, but the structure of the prism T and the imaging surface IMA are not shown.

[0142] like Figure 8 As shown, the imaging lens group includes a lens barrel, a four-piece lens group arranged in the lens barrel, and a spacer element group. The four-piece lens group includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 in order from the object side to the image side along the first optical axis. A stop STO (not shown) is arranged on the image side of the fourth lens E4.

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

[0144] The structure of the four-lens group of the optical imaging lens of this embodiment is the same as that of the four-lens group of the optical imaging lens in Embodiment 4. The basic parameters thereof are detailed in Tables 3 and 4 and will not be described in detail.

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

[0146] Example 6

[0147] The following reference Figure 2 The optical imaging lens of Example 6 of the present application is described. 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] Fig. 9 A partial structural schematic diagram of the optical imaging lens of Example 6 of the present application is shown. Fig. 9 The structure of the imaging lens group in the optical imaging lens is shown in FIG, but the structure of the prism T and the imaging surface IMA are not shown.

[0149] like Fig. 9 As shown, the imaging lens group includes a lens barrel, a four-piece lens group arranged in the lens barrel, and a spacer element group. The four-piece lens group includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 in order from the object side to the image side along the first optical axis. A stop STO (not shown) is arranged on the image side of the fourth lens E4.

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

[0151] The structure of the four-lens group of the optical imaging lens of this embodiment is the same as that of the four-lens group of the optical imaging lens in Embodiment 4. The basic parameters thereof are detailed in Tables 3 and 4 and will not be described in detail.

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

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

[0154] Example 7

[0155] The following references Figure 2 The optical imaging lens of Example 7 of the present application is described. 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] Fig.11 A partial structural schematic diagram of the optical imaging lens of Example 7 of the present application is shown. Fig.11 The structure of the imaging lens group in the optical imaging lens is shown in FIG, but the structure of the prism T and the imaging surface IMA are not shown.

[0157] like Fig.11 As shown, the imaging lens group includes a lens barrel, a four-piece lens group arranged in the lens barrel, and a spacer element group. The four-piece lens group includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 in order from the object side to the image side along the first optical axis. A stop STO (not shown) is arranged on the image side of the fourth lens E4.

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

[0159] 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. The first spacer element P1 is placed between the first lens E1 and the second lens E2, and the object side surface of the first spacer element P1 is at least partially in contact with the image side surface S2 of the first lens E1. The second spacer element P2 is placed between the second lens E2 and the third lens E3, and the object side surface of the second spacer element P2 is at least partially in contact with the image side surface S4 of the second lens E2. The third spacer element P3 is placed between the third lens E3 and the fourth lens E4, and the object side surface of the third spacer element P3 is at least partially in contact with the image side surface S6 of the third lens E3. The third auxiliary spacer element P3b is placed on the image side of the third spacer element P3, and the object side surface of the third auxiliary spacer element P3b is at least partially in contact with the image side surface of the third spacer element P3.

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

[0161] Light from an object passes through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4 in sequence, and after multiple reflections (for example, 3 times) inside the prism T, passes through the filter P and is imaged on the imaging surface IMA.

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

[0163] Table 5

[0164]

[0165]

[0166] In this embodiment, the object side surface and the image side surface of any lens from the second lens E2 to the fourth lens E4 are both aspherical surfaces. Table 6 shows the high-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 7.

[0167] Table 6

[0168]

[0169] Example 8

[0170] The following references Figure 2 The optical imaging lens of Example 8 of the present application is described. 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] Fig.12 A partial structural schematic diagram of the optical imaging lens of Example 8 of the present application is shown. Fig.12 The structure of the imaging lens group in the optical imaging lens is shown in FIG, but the structure of the prism T and the imaging surface IMA are not shown.

[0172] like Fig.12 As shown, the imaging lens group includes a lens barrel, a four-piece lens group arranged in the lens barrel, and a spacer element group. The four-piece lens group includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 in order from the object side to the image side along the first optical axis. A stop STO (not shown) is arranged on the image side of the fourth lens E4.

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

[0174] The structure of the four-lens group of the optical imaging lens of this embodiment is the same as that of the four-lens group of the optical imaging lens in Embodiment 7. The basic parameters thereof are detailed in Tables 5 and 6 and will not be described in detail.

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

[0176] Example 9

[0177] The following references Figure 2 The optical imaging lens of Example 9 of the present application is described. 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] Fig.13 A partial structural schematic diagram of the optical imaging lens of Example 9 of the present application is shown. Fig.13 The structure of the imaging lens group in the optical imaging lens is shown in FIG, but the structure of the prism T and the imaging surface IMA are not shown.

[0179] like Fig.13 As shown, the imaging lens group includes a lens barrel, a four-piece lens group arranged in the lens barrel, and a spacer element group. The four-piece lens group includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 in order from the object side to the image side along the first optical axis. A stop STO (not shown) is arranged on the image side of the fourth lens E4.

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

[0181] The structure of the four-lens group of the optical imaging lens of this embodiment is the same as that of the four-lens group of the optical imaging lens in Embodiment 7. The basic parameters thereof are detailed in Tables 5 and 6 and will not be described in detail.

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

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

[0184] Table 7 shows the parameter values ​​of f, f1, f2, f3, f4, SAG32, and SAG41 of each embodiment from Embodiment 1 to Embodiment 9. The units of the parameters listed in Table 7 are all millimeters (mm).

[0185] Table 7

[0186]

[0187] Table 8 gives the values ​​of parameters of at least some elements in the lens barrel and the spacer element group in each embodiment from Embodiment 1 to Embodiment 9. Among them, some parameters can be calculated according to Figure 1 The parameters listed in Table 8 are measured using the marking method shown in the figure, 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 relationship shown in Table 9.

[0191] Table 9

[0192]

[0193] The present 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 smart watch or smart glasses, an independent imaging device such as a distance detection camera, an independent imaging device such as a vehicle-mounted camera, a mobile electronic device such as a mobile phone or a tablet computer, an imaging module integrated in a distance detection device, or an imaging module integrated in an auxiliary driving system.

[0194] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

Claims

1. An optical imaging lens, characterized in that: It includes an imaging lens group, a prism, and an imaging surface, and the imaging lens group and the imaging surface are on the same side of the prism; wherein, The imaging lens group includes: A lens group composed of a first lens with a negative focal power, a second lens with a positive focal power, a third lens with a negative focal power, and a fourth lens with a positive focal power arranged in sequence from the object side to the image side along the first optical axis. Among them, 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; An interval element group including a first interval element and a second interval element. The first interval element is placed between the first lens and the second lens and contacts the image side surface of the first lens, and the second interval element is placed between the second lens and the third lens and contacts the image side surface of the second lens; and A lens barrel that houses the lens group and the interval 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 interval element and the second interval element along the first optical axis, 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 interval element.

2. The optical imaging lens according to claim 1, wherein: The interval element group further includes a third interval element, and the third interval element is placed 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 interval element, and d3s is the inner diameter of the object side surface of the third interval element.

3. The optical imaging lens according to claim 1, wherein: The interval element group further includes a third interval element, and the third interval element is placed 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 interval element and the third interval element along the first optical axis, 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 interval element group further includes a third interval element, and the third interval element is placed 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 point 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.

5. The optical imaging lens according to claim 1, wherein: 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.

6. The optical imaging lens according to claim 1, wherein: 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 point 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.

7. The optical imaging lens according to claim 1, wherein: 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.

8. The optical imaging lens according to claim 1, wherein: 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.

9. The optical imaging lens according to claim 1, wherein: 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.

10. The optical imaging lens according to any one of claims 1 to 9, characterized in that: 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.

Images