Optical imaging system

Abstract

The present application discloses an optical imaging system, which has a first optical axis, a second optical axis perpendicular to the first optical axis, and a third optical axis perpendicular to the second optical axis. The first optical axis and the third optical axis are parallel. Along the optical axis from the object side to the image side, it sequentially includes: The optical imaging system includes: a first imaging lens group, including a first refractive optical element that deflects the light incident in the direction of the first optical axis to propagate in the direction of the second optical axis; a second imaging lens group, which sequentially includes, along the second optical axis from the object side to the image side: a first lens with a focal power, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens; and a third imaging lens group, including a second refractive optical element that deflects the light incident in the direction of the second optical axis to propagate in the direction of the third optical axis; The distance TTLz from the object side end of the first imaging lens group to the imaging surface in the direction of the third optical axis and the total effective focal length f of the optical imaging system satisfy: TTLz / f < 0.7.

Description

Technical Field

[0001] This application relates to the field of optical components, and more particularly, to an optical imaging system. Background Art

[0002] With the upgrading of consumer electronic products and the development of image software functions and video software functions on consumer electronic products, consumers' requirements for the shooting quality of electronic products such as mobile phones are constantly increasing. At the same time, consumers expect electronic products such as mobile phones to be thinner, lighter, and smaller.

[0003] An imaging module is usually provided on portable devices such as mobile phones so that the mobile phone has an imaging function. An image sensor of Charge-coupled Device (CCD) type or Complementary Metal Oxide Semiconductor (CMOS) type is usually provided in the imaging module, and an optical imaging system is provided. The optical imaging system can converge the light on the object side, and the imaging light travels along the optical path of the optical imaging system and irradiates onto the image sensor. Then, the image sensor converts the optical signal into an electrical signal to form image data.

[0004] In the optical imaging system configured in the imaging module, there is a telephoto lens. The structural size of the telephoto lens is often relatively long. In order to meet the miniaturization requirements and imaging requirements, an optical imaging system that can balance ultra-thin, long focal length, and ultra-small distortion is needed. Summary of the Invention

[0005] This application provides an optical imaging system, which sequentially includes, from the object side to the image side along the optical axis: having a first optical axis, a second optical axis perpendicular to the first optical axis, and a third optical axis perpendicular to the second optical axis, wherein the first optical axis and the third optical axis are parallel. The optical imaging system includes: a first imaging lens group arranged along the first optical axis, including a first refractive optical element configured to deflect the light incident in the direction of the first optical axis to propagate in the direction of the second optical axis; a second imaging lens group, which sequentially includes, from the object side to the image side along the second optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens having optical power; and a third imaging lens group arranged along the third optical axis, including a second refractive optical element configured to deflect the light incident in the direction of the second optical axis to propagate in the direction of the third optical axis; wherein, the distance TTLz from the object side end of the first imaging lens group to the imaging plane of the optical imaging system in the direction parallel to the direction of the third optical axis and the total effective focal length f of the optical imaging system satisfy: TTLz / f < 0.7.

[0006] In one embodiment, at least one aspherical mirror surface is provided between the object side surface of the first lens and the image side surface of the seventh lens.

[0007] In one embodiment, the optical distortion Dist of the optical imaging system may satisfy: |Dist| < 0.1%.

[0008] In one embodiment, the effective focal length f1 of the first lens and the effective focal length f4 of the fourth lens may satisfy: 0 < f1 / f4 < 1.0.

[0009] In one embodiment, the effective focal length f2 of the second lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens may satisfy: 0.5 < (f2 + f6) / f7 < 2.0.

[0010] In one embodiment, the first refractive optical element is a first prism, and the second refractive optical element is a second prism.

[0011] In one embodiment, the sum ∑CT of the thicknesses of any lens among the first lens to the seventh lens on the second optical axis and the sum PL1 of the thickness of the first prism on the first optical axis and the thickness of the first prism on the second optical axis may satisfy: 0.5 < ∑CT / PL1 < 1.0.

[0012] In one embodiment, the sum ∑AT of the spacing distances between any two adjacent lenses among the first lens to the seventh lens on the second optical axis and the sum PL2 of the thickness of the second prism on the second optical axis and the thickness of the second prism on the third optical axis may satisfy: 0.3 < ∑AT / PL2 < 0.8.

[0013] In one embodiment, the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R3 of the object side surface of the second lens, and the radius of curvature R4 of the image side surface of the second lens may satisfy: 0.3 < R1 / (R3 - R4) < 1.3.

[0014] In one embodiment, the radius of curvature R6 of the image side surface of the third lens and the radius of curvature R7 of the object side surface of the fourth lens may satisfy: 0.5 < R6 / R7 < 1.5.

[0015] In one embodiment, the radius of curvature R14 of the image side surface of the seventh lens and the total effective focal length f of the optical imaging system may satisfy: 0 < R14 / f < 1.0.

[0016] In one embodiment, the central thickness CT1 of the first lens on the second optical axis, the central thickness CT6 of the sixth lens on the second optical axis, and the central thickness CT7 of the seventh lens on the second optical axis may satisfy: 0 < CT6 / (CT1 + CT7) < 1.0.

[0017] In one embodiment, the central thickness CT4 of the fourth lens on the second optical axis, the central thickness CT5 of the fifth lens on the second optical axis, and the spacing distance T45 between the fourth lens and the fifth lens on the second optical axis may satisfy: 0.6 < (CT4 + CT5) / T45 < 1.6.

[0018] In one embodiment, the first lens has a positive optical power, and its object side is convex; the second lens has a negative optical power; the image side of the third lens is concave; the fourth lens has a positive optical power, and its object side is convex; the image side of the seventh lens is concave.

[0019] On the other hand, the present application provides an optical imaging system having a first optical axis, a second optical axis perpendicular to the first optical axis, and a third optical axis perpendicular to the second optical axis. Among them, the first optical axis and the third optical axis are parallel. The optical imaging system includes: a first imaging lens group arranged along the first optical axis, including a first refractive optical element configured to deflect light incident in the direction of the first optical axis to propagate in the direction of the second optical axis; a second imaging lens group, which sequentially includes, from the object side to the image side along the second optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens having optical powers; and a third imaging lens group arranged along the third optical axis, including a second refractive optical element configured to deflect light incident in the direction of the second optical axis to propagate in the direction of the third optical axis. Among them, the optical distortion Dist of the optical imaging system may satisfy: |Dist| < 0.1%.

[0020] In one embodiment, the effective focal length f1 of the first lens and the effective focal length f4 of the fourth lens may satisfy: 0 < f1 / f4 < 1.0.

[0021] In one embodiment, the distance TTLz from the object side end of the first imaging lens group to the imaging surface of the optical imaging system in the direction parallel to the third optical axis and the total effective focal length f of the optical imaging system may satisfy: TTLz / f < 0.7.

[0022] In one embodiment, the effective focal length f2 of the second lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens may satisfy: 0.5 < (f2 + f6) / f7 < 2.0.

[0023] In one embodiment, the first refractive optical element is a first prism, and the second refractive optical element is a second prism.

[0024] In one embodiment, the sum ∑CT of the thicknesses of any lens among the first lens to the seventh lens on the second optical axis and the sum PL1 of the thickness of the first prism on the first optical axis and the thickness of the first prism on the second optical axis may satisfy: 0.5 < ∑CT / PL1 < 1.0.

[0025] In one embodiment, the sum ∑AT of the distances between any two adjacent lenses among the first lens to the seventh lens on the second optical axis and the sum PL2 of the thickness of the second prism on the second optical axis and the thickness of the second prism on the third optical axis may satisfy: 0.3 < ∑AT / PL2 < 0.8.

[0026] In one embodiment, the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R3 of the object side surface of the second lens, and the radius of curvature R4 of the image side surface of the second lens may satisfy: 0.3 < R1 / (R3 - R4) < 1.3.

[0027] In one embodiment, the radius of curvature R6 of the image side surface of the third lens and the radius of curvature R7 of the object side surface of the fourth lens may satisfy: 0.5 < R6 / R7 < 1.5.

[0028] In one embodiment, the radius of curvature R14 of the image side surface of the seventh lens and the total effective focal length f of the optical imaging system may satisfy: 0 < R14 / f < 1.0.

[0029] In one embodiment, the central thickness CT1 of the first lens on the second optical axis, the central thickness CT6 of the sixth lens on the second optical axis, and the central thickness CT7 of the seventh lens on the second optical axis may satisfy: 0 < CT6 / (CT1 + CT7) < 1.0.

[0030] In one embodiment, the central thickness CT4 of the fourth lens on the second optical axis, the central thickness CT5 of the fifth lens on the second optical axis, and the distance T45 between the fourth lens and the fifth lens on the second optical axis may satisfy: 0.6 < (CT4 + CT5) / T45 < 1.6.

[0031] In one embodiment, the first lens has a positive optical power, and its object side surface is convex; the second lens has a negative optical power; the image side surface of the third lens is concave; the fourth lens has a positive optical power, and its object side surface is convex; the image side surface of the seventh lens is concave.

[0032] This application uses refractive optical elements and seven lenses. By setting a prism, the incident direction of light forms a 90-degree angle with the arrangement direction of the multiple lenses, so that the size of the optical imaging system in the light incident direction is reduced. At the same time, by reasonably distributing the optical power, surface shape, central thickness of each lens, and the axial distance between each lens, etc., the above optical imaging system has at least one beneficial effect such as long focal length and ultra-small distortion. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In conjunction with the drawings, through the following detailed description of non-limiting embodiments, other features, objects, and advantages of this application will become more apparent. In the drawings:

[0034] Figure 1 Shows a schematic structural diagram of an optical imaging system according to an embodiment of the present application;

[0035] Figure 2 Shows a schematic structural diagram of the optical imaging system according to Embodiment 1 of the present application; Figures 3A to 3D Respectively show the axial chromatic aberration curve, astigmatism curve, distortion curve, and lateral chromatic aberration curve of the optical imaging system of Embodiment 1;

[0036] Figure 4 Shows a schematic structural diagram of the optical imaging system according to Embodiment 2 of the present application; Figures 5A to 5D Respectively show the axial chromatic aberration curve, astigmatism curve, distortion curve, and lateral chromatic aberration curve of the optical imaging system of Embodiment 2;

[0037] Figure 6 Shows a schematic structural diagram of the optical imaging system according to Embodiment 3 of the present application; Figures 7A to 7D Respectively show the axial chromatic aberration curve, astigmatism curve, distortion curve, and lateral chromatic aberration curve of the optical imaging system of Embodiment 3;

[0038] Figure 8 Shows a schematic structural diagram of the optical imaging system according to Embodiment 4 of the present application; Figures 9A to 9D Respectively show the axial chromatic aberration curve, astigmatism curve, distortion curve, and lateral chromatic aberration curve of the optical imaging system of Embodiment 4;

[0039] Figure 10 Shows a schematic structural diagram of the optical imaging system according to Embodiment 5 of the present application; Figures 11A to 11D Respectively show the axial chromatic aberration curve, astigmatism curve, distortion curve, and lateral chromatic aberration curve of the optical imaging system of Embodiment 5;

[0040] Figure 12 Shows a schematic structural diagram of the optical imaging system according to Embodiment 6 of the present application; Figures 13A to 13D Respectively show the axial chromatic aberration curve, astigmatism curve, distortion curve, and lateral chromatic aberration curve of the optical imaging system of Embodiment 6;

[0041] Figure 14 Shows a schematic structural diagram of the optical imaging system according to Embodiment 7 of the present application; Figures 15A to 15D Respectively show the axial chromatic aberration curve, astigmatism curve, distortion curve, and lateral chromatic aberration curve of the optical imaging system of Embodiment 7;

[0042] Figure 16 Shows a schematic structural diagram of the optical imaging system according to Embodiment 8 of the present application; Figures 17A to 17DThe axial chromatic aberration curve, astigmatism curve, distortion curve, and longitudinal chromatic aberration curve of the optical imaging system of Embodiment 8 are respectively shown;

[0043] Figure 18 The structural schematic diagram of the optical imaging system according to Embodiment 9 of the present application is shown; Figures 19A to 19D The axial chromatic aberration curve, astigmatism curve, distortion curve, and longitudinal chromatic aberration curve of the optical imaging system of Embodiment 8 are respectively shown;

[0044] Figure 20 The structural schematic diagram of the optical imaging system according to Embodiment 10 of the present application is shown; Figures 21A to 21D The axial chromatic aberration curve, astigmatism curve, distortion curve, and longitudinal chromatic aberration curve of the optical imaging system of Embodiment 8 are respectively shown;

[0045] Figures 22A to 22J The MTF curves of the optical imaging systems according to Embodiments 1 to 10 of the present application are shown. Detailed Embodiments

[0046] To better understand the present application, more detailed descriptions of various aspects of the present application will be made 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 reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0047] It should be noted that in this specification, the expressions such as first, second, and third are only used to distinguish one feature from another feature and do not represent any limitation on the features. Therefore, without departing from the teachings of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0048] In the drawings, for ease of illustration, the thickness, size, and shape of the lenses have been slightly exaggerated. 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 spherical or aspherical shapes shown in the drawings. The drawings are only for illustration and are not drawn to an exact scale.

[0049] In this article, the paraxial region refers to the region near the optical axis. 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 surface of each lens closest to the object to be photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0050] It should also be understood that the terms "comprising," "comprises," "having," "includes," and / or "including," when used in this specification, denote the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Further, when an expression such as "at least one of..." appears after a list of listed features, it modifies the entire list of listed features, rather than individual elements in the list. In addition, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application." Also, the term "exemplary" is intended to refer to an example or illustration.

[0051] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0052] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0053] The features, principles, and other aspects of the present application will be described in detail below.

[0054] The optical imaging system according to an exemplary embodiment of the present application may include, for example, three imaging lens groups, namely, a first imaging lens group, a second imaging lens group, and a third imaging lens group. These three imaging lens groups may be arranged in sequence from the object side to the image side along the total optical axis.

[0055] Referring to Figure 1 , the optical imaging system may have a first optical axis Z1, a second optical axis Y, and a third optical axis Z2. The first optical axis Z1 and the third optical axis Z2 are parallel and perpendicular to the second optical axis Y respectively. Further, the first optical axis Z1 and the third optical axis Z2 intersect the first optical axis Y respectively.

[0056] The first imaging lens group is disposed along the first optical axis Z1 and includes a first refractive optical element L1. The first refractive optical element L1 is configured to deflect light incident in the direction of the first optical axis Z1 to propagate in the direction of the second optical axis Y.

[0057] The second imaging lens group may include seven lenses with optical power, namely, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a seventh lens E7. These seven lenses are arranged in sequence from the object side to the image side along the second optical axis Y. An air gap may be provided between any two adjacent lenses among the first lens E1 to the seventh lens E7.

[0058] The third imaging lens group is disposed along the third optical axis Z2 and includes a second refractive optical element L2. The second refractive optical element L2 is configured to deflect the light incident along the second optical axis Y in the direction of the third optical axis Z2.

[0059] The optical imaging system provided in this application has a periscope structure.

[0060] In an exemplary embodiment, the first lens E1 may have a positive optical power, and its object side surface may be convex; the second lens E2 may have a negative optical power; exemplarily, the third lens E3 has a positive or negative optical power, and its image side surface may be concave; the fourth lens E4 may have a positive optical power, and its object side surface may be convex; the fifth lens E5 has a positive or negative optical power; the sixth lens E6 has a positive or negative optical power; the seventh lens E7 has a positive or negative optical power, and its image side surface may be concave. The first lens E1 with positive optical power, the second lens E1 with negative optical power, and the fourth lens E4 with positive optical power can make the light converge well. At the same time, by reasonably distributing the optical powers of the first lens E1, the second lens E2, and the fourth lens E4, it is beneficial to increase the total effective focal length of the optical imaging system and ensure the long focal length characteristics of the optical imaging system. In addition, by controlling the convex and concave surfaces of the lenses of the optical imaging system, it is possible to effectively avoid the generation of ghost images and at the same time facilitate the improvement of the field curvature of the optical imaging system.

[0061] For the optical imaging system provided in this application, by controlling the element distribution of the first imaging lens group, the second imaging lens group, and the third imaging lens group, it helps the optical imaging system to have the characteristic of ultra-small distortion.

[0062] In an exemplary embodiment, the optical imaging system of this application may satisfy the condition TTLz / f < 0.7, where TTLz is the distance from the object side end of the first imaging lens group to the imaging surface of the optical imaging system in the direction parallel to the third optical axis Z2 (also the first optical axis Z1 direction), and f is the total effective focal length of the optical imaging system. The optical imaging system satisfying TTLz / f < 0.7 can ensure that while increasing its total effective focal length, the total length of the optical imaging system in the third optical axis Z2 direction is reasonably controlled, thereby achieving miniaturization. More specifically, TTLz and f may satisfy: 0.51 < TTLz / f < 0.59.

[0063] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional formula |Dist| < 0.1%, where Dist is the optical distortion of the optical imaging system. The optical imaging system satisfying |Dist| < 0.1% can endow it with the characteristic of ultra-small distortion, help reduce the aberration of the optical imaging system, and further greatly improve the imaging quality of the optical imaging system. When the optical imaging system with ultra-small optical distortion is in use, it can restore the true appearance of the object to the greatest extent. More specifically, Dist can satisfy: |Dist| < 0.08%.

[0064] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional formula 0 < f1 / f4 < 1.0, where f1 is the effective focal length of the first lens E1 and f4 is the effective focal length of the fourth lens E4. By controlling the ratio of the effective focal length of the first lens E1 to the effective focal length of the fourth lens E4 within this range, the contribution rate of the fourth lens E4 to the optical power can be reasonably controlled, and the high-order spherical aberration generated by the optical imaging system can be balanced. More specifically, f1 and f4 can satisfy: 0.33 < f1 / f4 < 0.82.

[0065] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional formula 0.5 < (f2 + f6) / f7 < 2.0, where f2 is the effective focal length of the second lens E2, f6 is the effective focal length of the sixth lens E6, and f7 is the effective focal length of the seventh lens E7. The optical imaging system satisfying 0.5 < (f2 + f6) / f7 < 2.0 can make its optical power be reasonably distributed to effectively increase the total effective focal length, and at the same time can well correct its aberration, thereby improving its imaging quality. More specifically, f2, f6, and f7 can satisfy: 0.75 < (f2 + f6) / f7 < 1.52.

[0066] In an exemplary embodiment, the first refractive optical element L1 can be a first prism. The first prism includes an incident surface located on the first optical axis Z1, an exit surface located on the third optical axis Z2, and a reflection surface between the incident surface and the exit surface. The reflection surface can form an angle of 45° with the first optical axis Z1 to deflect the light incident along the first optical axis Z1 by 90°.

[0067] In an exemplary embodiment, the second refractive optical element L2 can be a second prism. The second prism includes an incident surface located on the second optical axis Y, an exit surface located on the third optical axis Z2, and a reflection surface between the incident surface and the exit surface. The angle between the reflection surface of the second prism and the second optical axis Y can be 45°, and the second prism can be used to deflect the light incident along the second optical axis Y by 90°.

[0068] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula 0.5 < ∑CT / PL1 < 1.0, where ∑CT is the sum of the thicknesses of any lens among the first lens E1 to the seventh lens E7 on the second optical axis Y, and PL1 is the sum of the thickness of the first prism on the first optical axis Z1 and the thickness of the first prism on the second optical axis Y. Exemplarily, ∑CT = CT1 + CT2 + CT3 + CT4 + CT5 + CT6 + CT7, where CT1 is the central thickness of the first lens E1 on the second optical axis Y. Exemplarily, the thickness of the first prism on the first optical axis Z1 is equal to the distance between the incident surface and the reflection surface of the first prism on the first optical axis Z1. The optical imaging system satisfying 0.5 < ∑CT / PL1 < 1.0 can well control the incident angle of light, and at the same time is beneficial to controlling the overall optical length of the optical imaging system along the second optical axis Y, thereby reducing the length of the optical imaging system in the direction of the second optical axis Y. More specifically, ∑CT and PL1 may satisfy: 0.66 < ∑CT / PL1 < 0.85.

[0069] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula 0.3 < ∑AT / PL2 < 0.8, where ∑AT is the sum of the distances between any two adjacent lenses among the first lens E1 to the seventh lens E7 on the second optical axis Y, and PL2 is the sum of the thickness of the second prism on the second optical axis Y and the thickness of the second prism on the third optical axis Z2. Exemplarily, ∑AT = T12 + T23 + T34 + T45 + T56 + T67. The optical imaging system satisfying 0.3 < ∑AT / PL2 < 0.8 can effectively control the light exit angle from the first lens E1 to the seventh lens E7, making the structure of the optical imaging system more compact, and further the optical imaging system can be miniaturized. More specifically, ∑AT and PL2 may satisfy: 0.50 < ∑AT / PL2 < 0.70.

[0070] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula 0.3 < R1 / (R3 - R4) < 1.3, where R1 is the curvature radius of the object side of the first lens E1, R3 is the curvature radius of the object side of the second lens E2, and R4 is the curvature radius of the image side of the second lens E2. The optical imaging system satisfying 0.3 < R1 / (R3 - R4) < 1.3 is beneficial to better correcting its chromatic aberration, thereby improving its imaging quality, and at the same time can avoid the problem of increased system tolerance sensitivity caused by excessive concentration of optical power or excessive bending of the surface. More specifically, R1, R3, and R4 may satisfy: 0.55 < R1 / (R3 - R4) < 1.00.

[0071] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula 0.5 < R6 / R7 < 1.5, where R6 is the radius of curvature of the image side surface of the third lens E3, and R7 is the radius of curvature of the object side surface of the fourth lens E4. The optical imaging system satisfying 0.5 < R6 / R7 < 1.5 can keep the light angle of the marginal field of view within a reasonable range and effectively reduce the sensitivity of the optical imaging system. More specifically, R6 and R7 may satisfy: 0.8 < R6 / R7 < 1.25.

[0072] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula 0 < R14 / f < 1.0, where R14 is the radius of curvature of the image side surface of the seventh lens E7, and f is the total effective focal length of the optical imaging system. The optical imaging system satisfying 0 < R14 / f < 1.0 can well control the contribution of the seventh lens E7 to the fifth-order spherical aberration of the optical imaging system, and then compensate for the third-order spherical aberration of the system, so that the optical imaging system has good imaging quality on the axis. More specifically, R14 and f may satisfy: 0.35 < R14 / f < 0.85.

[0073] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula 0 < CT6 / (CT1 + CT7) < 1.0, where CT1 is the central thickness of the first lens E2 on the second optical axis Y, CT6 is the central thickness of the sixth lens E6 on the second optical axis Y, and CT7 is the central thickness of the seventh lens E7 on the second optical axis Y. The optical imaging system satisfying 0 < CT6 / (CT1 + CT7) < 1.0 can control the contribution of the distortion of each field of view of the optical imaging system within a reasonable range to improve its imaging quality. More specifically, CT1, CT6, and CT7 may satisfy: 0.24 < CT6 / (CT1 + CT7) < 0.55.

[0074] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula 0.6 < (CT4 + CT5) / T45 < 1.6, where CT4 is the central thickness of the fourth lens E4 on the second optical axis Y, CT5 is the central thickness of the fifth lens E5 on the second optical axis Y, and T45 is the interval distance between the fourth lens E4 and the fifth lens E5 on the second optical axis Y. The optical imaging system satisfying 0.6 < (CT4 + CT5) / T45 < 1.6 can improve the field curvature of each field of view, so that the contribution of the fourth lens E4 and the fifth lens E5 to the field curvature is within a reasonable range. More specifically, CT4, CT5, and T45 may satisfy: 0.78 < (CT4 + CT5) / T45 < 1.47.

[0075] In an exemplary embodiment, the above optical imaging system may further include at least one aperture STO. The aperture STO can be disposed at an appropriate position as needed. For example, it can be disposed between the object side and the first lens E1. More specifically, it can be disposed on the second optical axis Y. Optionally, the above optical imaging system may further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0076] The optical imaging system according to the above embodiment of the present application may employ multiple lenses, such as the nine lenses described above. By reasonably allocating the optical power, surface shape, central thickness of each lens, and the axial spacing between each lens, etc., the volume of the optical imaging system can be effectively reduced, the sensitivity of the optical imaging system can be decreased, and the processability of the optical imaging system can be improved, making the optical imaging system more conducive to production and applicable to portable electronic products. The first refractive optical element L1 and the second refractive optical element L1 enable the optical imaging system to have three optical axes, reducing the size of the optical imaging lens in the normal direction of the imaging surface. At the same time, the optical imaging system of the present application also has excellent optical properties such as long focal length, ultra-small distortion, and good imaging quality.

[0077] In an embodiment of the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface, that is, at least one of the object side surface of the first lens E1 to the image side surface of the seventh lens E7 is an aspherical mirror 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. Different from a spherical lens with a constant curvature from the center of the lens to the periphery, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using an aspherical lens, it is possible to eliminate as much as possible the aberration that appears during imaging, thereby improving the imaging quality. Optionally, at least one of the object side surface and the image side surface of each of the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6, and the seventh lens E7 is an aspherical mirror surface. Optionally, both the object side surface and the image side surface of each of the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6, and the seventh lens E7 are aspherical mirror surfaces.

[0078] However, those skilled in the art should understand that without departing from the technical solutions claimed in the present application, the number of lenses constituting the optical imaging system can be changed to obtain the various results and advantages described in this specification. For example, although seven lenses are described as an example in the embodiment, the optical imaging system is not limited to including seven lenses. If necessary, the optical imaging system may further include other numbers of lenses.

[0079] The following further describes specific embodiments of the optical imaging system applicable to the above embodiments with reference to the accompanying drawings.

[0080] Example 1

[0081] The following refers to Figures 2 to 3D and Figure 22A describe the optical imaging system according to Embodiment 1 of the present application. Figure 2 FIG. shows a schematic structural diagram of the optical imaging system according to Embodiment 1 of the present application.

[0082] As Figure 2 shown, the optical imaging system sequentially includes, from the object side to the image side along the second optical axis: a first prism L1, a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0083] The first prism L1 includes an incident surface S1, a reflection surface S2, and an exit surface S3. The first lens E1 has a positive focal power, its object side surface S4 is convex, and its image side surface S5 is concave. The second lens E2 has a negative focal power, its object side surface S6 is convex, and its image side surface S7 is concave. The third lens E3 has a negative focal power, its object side surface S8 is concave, and its image side surface S9 is convex. The fourth lens E4 has a positive focal power, its object side surface S10 is convex, and its image side surface S11 is concave. The fifth lens E5 has a positive focal power, its object side surface S12 is concave, and its image side surface S13 is convex. The sixth lens E6 has a negative focal power, its object side surface S14 is concave, and its image side surface S15 is convex. The seventh lens E7 has a negative focal power, its object side surface S16 is convex, and its image side surface S17 is concave. The second prism L2 includes an incident surface S18, a reflection surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. Light from the object passes through the incident surface S1 of the first prism L1 along the first optical axis, is refracted by the reflection surface S2 of the first prism L1 to be along the second optical axis, then sequentially passes through the surfaces S3 to S18, is refracted by the reflection surface S19 of the second prism L2 to be along the third optical axis, then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0084] Table 1 shows the basic parameter table of the optical imaging system of Embodiment 1, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0085]

[0086]

[0087] Table 1

[0088] In Example 1, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the value of the on-axis distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 13.59 mm, the value of half of the diagonal length ImgH of the effective pixel region on the imaging surface S23 is 3.65 mm, and the value of the maximum field of view angle FOV is 16.7°.

[0089] In Example 1, the object side surface and the image side surface of any one of the first lens E1 to the seventh lens E7 are aspherical surfaces, and the surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0090]

[0091] where x is the sagitta, the distance from the vertex of the aspherical surface at a position with a height of h along the optical axis direction; 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 constant; Ai is the correction coefficient of the i-th order of the aspherical surface. Table 2 below gives the higher-order term coefficients A4, A6, A8, A 10 , A 12 , A 14 , A 16 , A 18 , and A 20 .

[0092]

[0093]

[0094] Table 2

[0095] Figure 3A shows the axial chromatic aberration curve of the optical imaging system of Example 1, which represents the deviation of the converging focal points of light rays with different wavelengths after passing through the lens. Figure 3B shows the astigmatism curve of the optical imaging system of Example 1, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 3C shows the distortion curve of the optical imaging system of Example 1, which represents the distortion magnitude values corresponding to different image heights. Figure 3D shows the longitudinal chromatic aberration curve of the optical imaging system of Example 1, which represents the deviation of different image heights of light rays on the imaging surface after passing through the lens. Figure 22AThe modulation transfer function curve (MTF) of the optical imaging system of Embodiment 1 is shown, which represents the change of modulation degree with respect to spatial frequency. According to Figures 3A to 3D 、 Figure 22A it can be known that the optical imaging system given in Embodiment 1 can achieve good imaging quality.

[0096] Example 2

[0097] The following refers to Figures 4 to 5D to describe the optical imaging system according to Embodiment 2 of the present application. In this embodiment and the following embodiments, for the sake of brevity, some descriptions similar to those in Embodiment 1 will be omitted. Figure 4 The structural schematic diagram of the optical imaging system according to Embodiment 2 of the present application is shown.

[0098] As Figure 4 shown, the optical imaging system sequentially includes, from the object side to the image side along the second optical axis: a first prism L1, a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0099] The first prism L1 includes an incident surface S1, a reflecting surface S2, and an exit surface S3. The first lens E1 has a positive optical power, its object side surface S4 is convex, and its image side surface S5 is convex. The second lens E2 has a negative optical power, its object side surface S6 is convex, and its image side surface S7 is concave. The third lens E3 has a negative optical power, its object side surface S8 is convex, and its image side surface S9 is concave. The fourth lens E4 has a positive optical power, its object side surface S10 is convex, and its image side surface S11 is convex. The fifth lens E5 has a positive optical power, its object side surface S12 is convex, and its image side surface S13 is concave. The sixth lens E6 has a negative optical power, its object side surface S14 is concave, and its image side surface S15 is concave. The seventh lens E7 has a negative optical power, its object side surface S16 is convex, and its image side surface S17 is concave. The second prism L2 includes an incident surface S18, a reflecting surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. The light from the object passes through the incident surface S1 of the first prism L1 along the first optical axis, is refracted by the reflecting surface S2 of the first prism L1 to be along the second optical axis, and then sequentially passes through the surfaces S3 to S18, is refracted by the reflecting surface S19 of the second prism L2 to be along the third optical axis, and then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0100] In Embodiment 2, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the value of the axial distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 13.93 mm, the value of half of the diagonal length ImgH of the effective pixel region on the imaging surface S23 is 3.65 mm, and the value of the maximum field of view angle FOV is 16.7°.

[0101] Table 3 shows the basic parameter table of the optical imaging system of Embodiment 2, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm). Table 4 shows the high-order term coefficients of the aspherical mirror surfaces that can be used in Embodiment 2, where each aspherical surface type can be defined by the formula (1) given in Embodiment 1 above.

[0102]

[0103]

[0104] Table 3

[0105] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S4 -4.4479E-03 6.6523E-03 1.9914E-04 9.3993E-05 5.6736E-05 1.9098E-05 8.2671E-06 -8.3695E-06 -1.9458E-06 S5 -1.5279E-01 2.2576E-02 -4.4710E-03 1.4494E-03 -2.6984E-04 2.2188E-04 -1.3250E-04 2.7785E-05 2.6326E-05 S6 4.7042E-02 -5.1561E-03 -6.9230E-04 8.1456E-04 -4.4227E-04 3.3532E-04 -1.6706E-04 9.3859E-05 3.2154E-05 S7 7.9115E-02 -6.1501E-03 -6.2178E-04 4.9732E-04 -5.0870E-04 2.0998E-04 -2.2356E-04 2.6087E-05 -4.7546E-06 S8 -1.5812E-01 1.8931E-02 -5.5798E-03 2.1212E-03 -4.8281E-04 1.0080E-04 -2.5892E-04 -7.8801E-05 -1.8545E-05 S9 2.1856E-02 -1.0526E-02 3.1672E-03 4.0479E-04 8.5066E-04 4.9108E-06 -3.2324E-04 -1.7389E-04 -7.4477E-07 S10 9.1905E-03 -6.6508E-03 3.0994E-03 -1.5449E-03 1.7372E-03 3.0043E-04 -9.1598E-05 -1.0268E-04 -3.8193E-06 S11 -5.7140E-02 1.9040E-02 -2.7562E-03 -3.8183E-04 7.4772E-04 1.9504E-05 4.2407E-06 -3.6088E-05 -1.3976E-05 S12 2.4151E-01 -8.1241E-03 4.4025E-03 2.0674E-03 -2.2459E-04 -2.3941E-04 7.6563E-05 -6.6365E-05 -3.2828E-05 S13 2.0546E-01 -1.6134E-02 4.6732E-03 2.1199E-03 5.2868E-05 2.0935E-05 1.9475E-04 -5.6526E-05 -5.6795E-05 S14 -1.1943E-02 2.9705E-02 -8.1891E-03 9.2250E-04 9.0718E-04 3.1498E-04 1.1367E-04 5.5133E-05 -4.3784E-05 S15 2.6462E-01 4.6091E-02 -4.8475E-03 -1.0760E-04 1.2566E-05 -3.4681E-04 -1.0686E-04 9.5845E-05 -9.7294E-06 S16 8.0485E-01 -1.5854E-02 1.2923E-03 -1.5283E-03 -7.9949E-04 -5.0478E-04 -1.6714E-04 6.6912E-05 8.9439E-06 S17 5.4060E-01 -4.7529E-02 2.2370E-03 -9.9154E-04 -4.4469E-04 -2.0193E-04 -5.4521E-05 1.9936E-06 -2.7357E-05

[0106] Table 4

[0107] Figure 5A shows the axial chromatic aberration curve of the optical imaging system of Embodiment 2, which represents the deviation of the converging focal points of light rays of different wavelengths after passing through the lens. Figure 5B shows the astigmatism curve of the optical imaging system of Embodiment 2, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane. Figure 5C shows the distortion curve of the optical imaging system of Embodiment 2, which represents the distortion magnitude values corresponding to different image heights. Figure 5D shows the lateral chromatic aberration curve of the optical imaging system of Embodiment 2, which represents the deviation of different image heights of light rays on the imaging surface after passing through the lens. Figure 22B shows the modulation transfer function curve (Modulation Transfer Function, MTF) of the optical imaging system of Embodiment 2, which represents the change of the modulation degree with respect to the spatial frequency. According to Figures 5A to 5D and Figure 22B it can be seen that the optical imaging system given in Embodiment 2 can achieve good imaging quality.

[0108] Example 3

[0109] The following refers to Figures 6 to 7D to describe the optical imaging system according to Embodiment 3 of the present application. Figure 6 shows a schematic structural diagram of the optical imaging system according to Embodiment 3 of the present application.

[0110] As shown Figure 6 in FIG. 1, the optical imaging system sequentially includes, from the object side to the image side along the second optical axis: a first prism L1, a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0111] The first prism L1 includes an incident surface S1, a reflecting surface S2, and an exit surface S3. The first lens E1 has a positive focal power, its object side surface S4 is convex, and its image side surface S5 is concave. The second lens E2 has a negative focal power, its object side surface S6 is convex, and its image side surface S7 is concave. The third lens E3 has a negative focal power, its object side surface S8 is concave, and its image side surface S9 is concave. The fourth lens E4 has a positive focal power, its object side surface S10 is convex, and its image side surface S11 is convex. The fifth lens E5 has a positive focal power, its object side surface S12 is convex, and its image side surface S13 is convex. The sixth lens E6 has a negative focal power, its object side surface S14 is concave, and its image side surface S15 is concave. The seventh lens E7 has a negative focal power, its object side surface S16 is convex, and its image side surface S17 is concave. The second prism L2 includes an incident surface S18, a reflecting surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. Light from the object passes through the incident surface S1 of the first prism L1 along the first optical axis, is refracted by the reflecting surface S2 of the first prism L1 to be along the second optical axis, and then sequentially passes through the surfaces S3 to S18, is refracted by the reflecting surface S19 of the second prism L2 to be along the third optical axis, then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0112] In Embodiment 3, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the axial distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 13.93 mm, the value of half of the diagonal length of the effective pixel region on the imaging surface S23, ImgH, is 3.65 mm, and the value of the maximum field of view FOV is 16.7°.

[0113] Table 5 shows the basic parameter table of the optical imaging system of Embodiment 3, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm). Table 6 shows the high-order term coefficients of the aspherical mirror surfaces that can be used in Embodiment 3, where each aspherical surface type can be defined by the formula (1) given in Embodiment 1 above.

[0114]

[0115]

[0116] Table 5

[0117] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S4 -1.0533E-02 8.0936E-03 2.8452E-04 2.7234E-04 1.1232E-04 1.2236E-05 4.0008E-07 -4.5868E-06 -1.3779E-06 S5 -1.5146E-01 2.3260E-02 -3.9621E-03 1.5465E-03 1.4365E-04 2.0407E-04 1.0889E-04 9.5772E-05 1.2158E-05 S6 4.8770E-02 -4.8519E-03 -3.6228E-04 6.5844E-04 1.0531E-04 3.4923E-04 1.1010E-04 9.5163E-05 1.8585E-06 S7 8.0049E-02 -4.5063E-03 -5.9864E-04 5.4798E-04 3.3983E-05 2.1761E-04 -3.8000E-05 -3.4531E-05 -1.5351E-05 S8 -1.5202E-01 2.0561E-02 -4.9255E-03 2.5358E-03 -1.8272E-04 9.4350E-05 -1.7545E-04 -6.3602E-05 3.6828E-06 S9 1.8850E-02 -1.1533E-02 4.5183E-03 -3.3775E-05 5.1139E-04 -3.2325E-04 -5.0320E-04 1.6234E-05 5.1048E-05 S10 1.2769E-02 -4.5716E-03 1.5381E-03 -1.7743E-03 1.8154E-03 3.8183E-04 -3.1249E-04 -3.3149E-05 2.5148E-06 S11 -5.3922E-02 1.7817E-02 -3.4596E-03 7.8672E-04 1.0943E-03 3.2926E-05 -2.7528E-04 -8.3531E-05 -2.6359E-05 S12 2.2939E-01 -7.0984E-03 3.3434E-03 2.0413E-03 -4.4504E-04 3.0353E-05 1.0458E-05 -2.9921E-05 -1.2033E-05 S13 1.9467E-01 -1.6303E-02 2.4314E-03 1.4922E-03 -3.5776E-04 1.8117E-04 1.1283E-04 -4.3391E-05 -9.8845E-06 S14 -1.1771E-02 3.2350E-02 -8.7073E-03 1.1495E-03 4.1511E-04 1.0000E-04 1.1472E-04 -2.3035E-05 -2.4970E-06 S15 2.5786E-01 4.7390E-02 -7.2858E-03 1.1428E-03 1.2249E-04 -2.7458E-04 3.9042E-06 3.2271E-05 -2.3930E-07 S16 7.8572E-01 -2.0968E-02 -3.1069E-03 -3.1657E-04 -4.7391E-04 -4.0203E-04 -5.7873E-05 5.9883E-05 1.0532E-05 S17 5.6277E-01 -5.8825E-02 6.6080E-04 -2.2396E-04 -4.7388E-04 -1.9634E-04 -2.8531E-06 1.0193E-05 -1.6506E-05

[0118] Table 6

[0119] Figure 7A The axial chromatic aberration curve of the optical imaging system of Embodiment 3 is shown, which represents the deviation of the converging focal points of light rays with different wavelengths after passing through the lens. Figure 7B The astigmatism curve of the optical imaging system of Embodiment 3 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 7C The distortion curve of the optical imaging system of Embodiment 3 is shown, which represents the distortion magnitude values corresponding to different image heights. Figure 7D The longitudinal chromatic aberration curve of the optical imaging system of Embodiment 3 is shown, which represents the deviation of different image heights of light rays on the imaging plane after passing through the lens. Figure 22C The modulation transfer function curve (Modulation Transfer Function, MTF) of the optical imaging system of Embodiment 3 is shown, which represents the change of the modulation degree with respect to the spatial frequency. According to Figures 7A to 7D and Figure 22C it can be known that the optical imaging system given in Embodiment 3 can achieve good imaging quality.

[0120] Example 4

[0121] The following refers to Figures 8 to 9D and describes the optical imaging system according to Embodiment 4 of the present application. Figure 8 The structural schematic diagram of the optical imaging system according to Embodiment 4 of the present application is shown.

[0122] As Figure 8 shown, the optical imaging system sequentially includes, from the object side to the image side along the second optical axis: a first prism L1, a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0123] The first prism L1 includes an incident surface S1, a reflection surface S2, and an exit surface S3. The first lens E1 has a positive optical power, with its object side surface S4 being convex and its image side surface S5 being concave. The second lens E2 has a negative optical power, with its object side surface S6 being convex and its image side surface S7 being concave. The third lens E3 has a negative optical power, with its object side surface S8 being convex and its image side surface S9 being concave. The fourth lens E4 has a positive optical power, with its object side surface S10 being convex and its image side surface S11 being concave. The fifth lens E5 has a positive optical power, with its object side surface S12 being convex and its image side surface S13 being convex. The sixth lens E6 has a negative optical power, with its object side surface S14 being concave and its image side surface S15 being concave. The seventh lens E7 has a negative optical power, with its object side surface S16 being convex and its image side surface S17 being concave. The second prism L2 includes an incident surface S18, a reflection surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. Light from an object travels along a first optical axis through the incident surface S1 of the first prism L1, is refracted by the reflection surface S2 of the first prism L1 to travel along a second optical axis, then sequentially passes through the surfaces S3 to S18, is refracted by the reflection surface S19 of the second prism L2 to travel along a third optical axis, then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0124] In Example 4, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the value of the on-axis distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 13.73 mm, the value of half of the diagonal length ImgH of the effective pixel region on the imaging surface S23 is 3.65 mm, and the value of the maximum field of view FOV is 16.7°.

[0125] Table 7 shows the basic parameter table of the optical imaging system of Example 4, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm). Table 8 shows the higher-order term coefficients that can be used for each aspherical mirror surface in Example 4, where each aspherical surface type can be defined by the formula (1) given in the above Example 1.

[0126]

[0127] Table 7

[0128]

[0129]

[0130] Table 8

[0131] Figure 9A Shows the axial chromatic aberration curve of the optical imaging system of Example 4, which represents the deviation of the convergence focal points of light rays of different wavelengths after passing through the lens.Figure 9B The astigmatism curve of the optical imaging system of Embodiment 4 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 9C The distortion curve of the optical imaging system of Embodiment 4 is shown, which represents the distortion magnitude values corresponding to different image heights. Figure 9D The longitudinal chromatic aberration curve of the optical imaging system of Embodiment 4 is shown, which represents the deviation of different image heights on the imaging plane after the light passes through the lens. Figure 22D The modulation transfer function curve (Modulation Transfer Function, MTF) of the optical imaging system of Embodiment 4 is shown, which represents the change of the modulation degree with respect to the spatial frequency. According to Figures 9A to 9D and Figure 22D it can be known that the optical imaging system given in Embodiment 4 can achieve good imaging quality.

[0132] Example 5

[0133] The following refers to Figures 10 to 11D the optical imaging system according to Embodiment 5 of the present application is described. Figure 10 The structural schematic diagram of the optical imaging system according to Embodiment 5 of the present application is shown.

[0134] As Figure 10 shown, the optical imaging system sequentially includes, from the object side to the image side along the second optical axis: a first prism L1, a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0135] The first prism L1 includes an incident surface S1, a reflection surface S2, and an exit surface S3. The first lens E1 has a positive optical power, with its object side surface S4 being convex and its image side surface S5 being concave. The second lens E2 has a negative optical power, with its object side surface S6 being convex and its image side surface S7 being concave. The third lens E3 has a negative optical power, with its object side surface S8 being convex and its image side surface S9 being concave. The fourth lens E4 has a positive optical power, with its object side surface S10 being convex and its image side surface S11 being convex. The fifth lens E5 has a positive optical power, with its object side surface S12 being concave and its image side surface S13 being convex. The sixth lens E6 has a negative optical power, with its object side surface S14 being concave and its image side surface S15 being convex. The seventh lens E7 has a negative optical power, with its object side surface S16 being convex and its image side surface S17 being concave. The second prism L2 includes an incident surface S18, a reflection surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. Light from an object travels along a first optical axis through the incident surface S1 of the first prism L1, is refracted by the reflection surface S2 of the first prism L1 to travel along a second optical axis, then sequentially passes through the surfaces S3 to S18, is refracted by the reflection surface S19 of the second prism L2 to travel along a third optical axis, then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0136] In Example 5, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the value of the on-axis distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 13.56 mm, the value of half of the diagonal length ImgH of the effective pixel region on the imaging surface S23 is 3.65 mm, and the value of the maximum field of view FOV is 16.7°.

[0137] Table 9 shows the basic parameter table of the optical imaging system of Example 5, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm). Table 10 shows the higher-order term coefficients that can be used for each aspherical mirror surface in Example 5, where each aspherical surface type can be defined by the formula (1) given in Example 1 above.

[0138]

[0139]

[0140] Table 9

[0141] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S4 -1.1985E-02 7.5543E-03 9.4104E-06 1.8977E-04 1.0734E-04 1.9366E-05 2.0661E-05 2.6786E-07 -6.1647E-07 S5 -1.5084E-01 2.2979E-02 -4.1940E-03 1.6885E-03 2.9697E-04 3.4125E-04 1.3529E-04 1.6196E-04 2.2398E-07 S6 4.9501E-02 -4.5451E-03 -2.5353E-04 8.1598E-04 8.0043E-05 4.5871E-04 6.7377E-05 2.0108E-04 -6.6742E-06 S7 7.8931E-02 -4.6711E-03 -3.7457E-04 6.6087E-04 -2.7395E-05 2.7054E-04 -6.1740E-05 5.7489E-05 1.0262E-05 S8 -1.5031E-01 2.0624E-02 -4.8731E-03 3.0253E-03 7.1518E-06 -1.3488E-04 -2.4019E-04 -1.0913E-04 3.7804E-05 S9 1.7389E-02 -1.0656E-02 4.9348E-03 3.2026E-04 6.0061E-04 -5.5071E-04 -6.1585E-04 -2.6154E-04 4.3660E-05 S10 1.3423E-02 -6.2537E-03 2.0403E-03 -1.7642E-03 1.6511E-03 4.5896E-04 -2.4804E-04 -1.7150E-04 -2.5426E-05 S11 -5.5325E-02 1.9865E-02 -4.4512E-03 1.1506E-03 1.0986E-03 4.2955E-04 -1.5434E-04 -1.2183E-04 -5.9423E-05 S12 2.3402E-01 -8.1341E-03 4.1135E-03 2.8748E-03 -5.2254E-04 2.2893E-04 3.2217E-05 -5.1778E-05 -3.7000E-05 S13 1.9081E-01 -1.7044E-02 3.1732E-03 2.5321E-03 -3.6354E-04 4.0527E-04 1.3529E-04 -5.9572E-05 -5.7369E-05 S14 3.5022E-03 3.2419E-02 -8.1448E-03 1.1752E-03 5.6662E-04 1.2644E-04 1.7689E-04 2.8633E-05 -2.5020E-05 S15 2.4359E-01 4.4716E-02 -8.2843E-03 6.6008E-04 4.1425E-05 -3.1385E-04 5.7858E-05 4.8285E-05 -1.0252E-05 S16 7.8833E-01 -2.4530E-02 -3.3492E-03 -2.1340E-03 -1.0759E-03 -4.6844E-04 -2.3975E-05 7.3874E-05 5.7127E-06 S17 5.6355E-01 -6.0925E-02 1.9775E-03 -1.4994E-03 -6.1438E-04 -2.4491E-04 -4.2692E-05 -1.3744E-05 -2.2435E-05

[0142] Table 10

[0143] Figure 11A Shows the axial chromatic aberration curve of the optical imaging system of Example 5, which represents the deviation of the converging focal points of light rays of different wavelengths after passing through the lens.Figure 11B The astigmatism curve of the optical imaging system of Embodiment 5 is shown, which represents the meridional field curvature and the sagittal field curvature. Figure 11C The distortion curve of the optical imaging system of Embodiment 5 is shown, which represents the distortion magnitude values corresponding to different image heights. Figure 11D The longitudinal chromatic aberration curve of the optical imaging system of Embodiment 5 is shown, which represents the deviation of different image heights on the imaging plane after the light passes through the lens. Figure 22E The modulation transfer function curve (Modulation Transfer Function, MTF) of the optical imaging system of Embodiment 5 is shown, which represents the change of the modulation degree with respect to the spatial frequency. According to Figures 11A to 11D and Figure 22E it can be known that the optical imaging system given in Embodiment 5 can achieve good imaging quality.

[0144] Example 6

[0145] The following Figures 12 to 13D describes the optical imaging system according to Embodiment 6 of the present application. Figure 12 The structural schematic diagram of the optical imaging system according to Embodiment 6 of the present application is shown.

[0146] As Figure 12 shown, the optical imaging system sequentially includes, from the object side to the image side along the second optical axis: a first prism L1, a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0147] The first prism L1 includes an incident surface S1, a reflecting surface S2, and an exit surface S3. The first lens E1 has a positive optical power, with its object side surface S4 being convex and its image side surface S5 being concave. The second lens E2 has a negative optical power, with its object side surface S6 being convex and its image side surface S7 being concave. The third lens E3 has a negative optical power, with its object side surface S8 being convex and its image side surface S9 being concave. The fourth lens E4 has a positive optical power, with its object side surface S10 being convex and its image side surface S11 being convex. The fifth lens E5 has a positive optical power, with its object side surface S12 being concave and its image side surface S13 being convex. The sixth lens E6 has a negative optical power, with its object side surface S14 being concave and its image side surface S15 being concave. The seventh lens E7 has a negative optical power, with its object side surface S16 being concave and its image side surface S17 being concave. The second prism L2 includes an incident surface S18, a reflecting surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. Light from an object travels along a first optical axis through the incident surface S1 of the first prism L1, is refracted by the reflecting surface S2 of the first prism L1 to travel along a second optical axis, then sequentially passes through the surfaces S3 to S18, is refracted by the reflecting surface S19 of the second prism L2 to travel along a third optical axis, then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0148] In Embodiment 6, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the value of the on-axis distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 13.59 mm, the value of half of the diagonal length of the effective pixel region on the imaging surface S23, ImgH, is 3.65 mm, and the value of the maximum field of view FOV is 16.7°.

[0149] Table 11 shows the basic parameter table of the optical imaging system of Embodiment 6, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm). Table 12 shows the higher-order term coefficients that can be used for each aspherical mirror surface in Embodiment 6, where each aspherical surface type can be defined by the formula (1) given in Embodiment 1 above.

[0150]

[0151]

[0152] Table 11

[0153] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S4 -1.4317E-02 7.4735E-03 -1.3987E-04 1.9954E-04 1.5160E-04 2.9709E-05 1.6811E-05 3.6151E-07 1.0669E-07 S5 -1.5102E-01 2.2640E-02 -4.1566E-03 1.7690E-03 3.8113E-04 4.0245E-04 1.7353E-04 1.7329E-04 1.9094E-05 S6 4.9011E-02 -4.5228E-03 -4.0677E-04 8.6595E-04 1.1443E-04 5.2401E-04 1.2509E-04 1.9341E-04 7.9763E-06 S7 7.8661E-02 -5.1458E-03 -4.9760E-04 5.6643E-04 2.9217E-05 2.8635E-04 -2.3809E-05 3.7640E-05 -5.1615E-06 S8 -1.4908E-01 2.1118E-02 -4.1865E-03 3.0970E-03 1.2995E-04 -2.0271E-04 -2.9708E-04 -1.4060E-04 -4.9490E-06 S9 1.5454E-02 -1.1106E-02 4.7042E-03 3.1000E-04 5.6948E-04 -6.5494E-04 -6.9639E-04 -3.5153E-04 -2.4464E-05 S10 1.5358E-02 -6.2115E-03 2.0719E-03 -1.6515E-03 1.7054E-03 4.2373E-04 -2.3312E-04 -2.3359E-04 -4.5781E-05 S11 -5.7510E-02 2.0689E-02 -3.7941E-03 1.0670E-03 1.0965E-03 3.9001E-04 -1.4927E-04 -1.4925E-04 -4.3710E-05 S12 2.3614E-01 -8.8496E-03 4.1107E-03 2.8145E-03 -5.1995E-04 2.2642E-04 -5.5285E-05 -9.1193E-05 -2.5436E-05 S13 1.9033E-01 -1.5534E-02 3.0941E-03 3.0384E-03 -3.1046E-04 5.4652E-04 4.5604E-05 -5.9774E-05 -2.9481E-05 S14 8.8759E-03 3.2427E-02 -7.8604E-03 1.4903E-03 3.8103E-04 2.4633E-04 2.1025E-04 7.9898E-05 -5.4087E-06 S15 2.5643E-01 4.3981E-02 -7.6276E-03 1.0597E-04 -2.8182E-04 -2.9046E-04 1.2115E-04 6.0500E-05 -1.3330E-05 S16 7.7111E-01 -2.2281E-02 -6.2922E-03 -3.7083E-03 -1.6925E-03 -4.3554E-04 1.2939E-04 1.2833E-04 1.0803E-05 S17 5.7666E-01 -5.8714E-02 -1.9690E-05 -1.8275E-03 -8.2443E-04 -2.8769E-04 -5.8941E-05 -2.9599E-05 -2.7995E-05

[0154] Table 12

[0155] Figure 13AThe axial chromatic aberration curve of the optical imaging system of Embodiment 6 is shown, which represents the deviation of the converging focal points of light rays with different wavelengths after passing through the lens. Figure 13B The astigmatism curve of the optical imaging system of Embodiment 6 is shown, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane. Figure 13C The distortion curve of the optical imaging system of Embodiment 6 is shown, which represents the distortion magnitude values corresponding to different image heights. Figure 13D The longitudinal chromatic aberration curve of the optical imaging system of Embodiment 6 is shown, which represents the deviation of different image heights on the imaging plane after the light rays pass through the lens. Figure 22F The modulation transfer function curve (Modulation Transfer Function, MTF) of the optical imaging system of Embodiment 6 is shown, which represents the change of the modulation degree with respect to the spatial frequency. According to Figures 13A to 13D and Figure 22F it can be known that the optical imaging system given in Embodiment 6 can achieve good imaging quality.

[0156] Example 7

[0157] The following refers to Figures 14 to 15D and describes the optical imaging system according to Embodiment 7 of the present application. Figure 14 The structural schematic diagram of the optical imaging system according to Embodiment 7 of the present application is shown.

[0158] As Figure 14 shown, the optical imaging system sequentially includes, from the object side to the image side along the second optical axis: a first prism L1, a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0159] The first prism L1 includes an incident surface S1, a reflection surface S2, and an exit surface S3. The first lens E1 has a positive optical power, with its object side surface S4 being convex and its image side surface S5 being concave. The second lens E2 has a negative optical power, with its object side surface S6 being convex and its image side surface S7 being concave. The third lens E3 has a positive optical power, with its object side surface S8 being convex and its image side surface S9 being concave. The fourth lens E4 has a positive optical power, with its object side surface S10 being convex and its image side surface S11 being convex. The fifth lens E5 has a positive optical power, with its object side surface S12 being concave and its image side surface S13 being convex. The sixth lens E6 has a negative optical power, with its object side surface S14 being concave and its image side surface S15 being concave. The seventh lens E7 has a negative optical power, with its object side surface S16 being concave and its image side surface S17 being concave. The second prism L2 includes an incident surface S18, a reflection surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. Light from an object travels along a first optical axis through the incident surface S1 of the first prism L1, is refracted by the reflection surface S2 of the first prism L1 to travel along a second optical axis, then sequentially passes through the surfaces S3 to S18, is refracted by the reflection surface S19 of the second prism L2 to travel along a third optical axis, then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0160] In Example 7, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the value of the on-axis distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 13.58 mm, the value of half of the diagonal length of the effective pixel region on the imaging surface S23, ImgH, is 3.65 mm, and the value of the maximum field of view FOV is 16.7°.

[0161] Table 13 shows the basic parameter table of the optical imaging system of Example 7, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm). Table 14 shows the higher-order term coefficients applicable to each aspherical mirror surface in Example 7, where each aspherical surface type can be defined by the formula (1) given in the above Example 1.

[0162]

[0163] Table 13

[0164] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S4 -1.3214E-02 7.5415E-03 -3.0083E-04 1.3863E-04 1.4060E-04 3.9409E-06 1.2607E-05 -2.0153E-06 -3.9391E-07 S5 -1.5171E-01 2.2528E-02 -4.5455E-03 1.6739E-03 3.2063E-04 3.4469E-04 1.5218E-04 1.7572E-04 1.7070E-05 S6 4.9033E-02 -4.4079E-03 -3.1124E-04 8.0589E-04 6.9097E-05 5.4168E-04 7.1586E-05 2.0593E-04 -1.7888E-07 S7 7.8669E-02 -5.0115E-03 -3.1474E-04 5.6915E-04 4.0196E-05 3.3068E-04 -6.6021E-05 5.0784E-05 -1.6006E-05 S8 -1.4854E-01 2.1469E-02 -4.1955E-03 3.1405E-03 1.5575E-04 -2.4882E-04 -2.4030E-04 -1.3135E-04 -2.2990E-05 S9 1.5063E-02 -1.0996E-02 5.1308E-03 2.0726E-04 6.2281E-04 -5.6567E-04 -4.5725E-04 -3.3514E-04 -4.9458E-05 S10 1.5767E-02 -6.3808E-03 1.9008E-03 -1.6308E-03 1.6041E-03 4.2449E-04 -1.3077E-04 -2.1809E-04 -5.8837E-05 S11 -5.7716E-02 2.0817E-02 -4.3160E-03 1.1126E-03 8.4921E-04 4.1980E-04 -7.1902E-05 -9.2624E-05 -3.8200E-05 S12 2.3635E-01 -9.7245E-03 4.1063E-03 2.9156E-03 -6.4613E-04 2.4449E-04 -5.7069E-06 -3.6810E-05 -1.9982E-05 S13 1.9008E-01 -1.6629E-02 2.8829E-03 2.9105E-03 -5.2244E-04 5.0606E-04 7.2417E-05 4.8317E-06 -3.8321E-05 S14 7.8869E-03 3.1758E-02 -8.6325E-03 1.2625E-03 3.2397E-04 1.4923E-04 1.5537E-04 9.1299E-05 -1.6423E-05 S15 2.5649E-01 4.3822E-02 -7.3257E-03 5.4588E-05 -1.8797E-04 -3.4948E-04 9.2187E-05 5.7240E-05 -1.2132E-05 S16 7.9407E-01 -1.9840E-02 -3.4273E-03 -2.8653E-03 -1.3487E-03 -5.0446E-04 1.7064E-05 9.0943E-05 8.7218E-06 S17 5.8735E-01 -5.4469E-02 1.6533E-04 -1.5737E-03 -6.8088E-04 -2.5636E-04 -4.3357E-05 -1.8154E-05 -2.5556E-05

[0165] Table 14

[0166] Figure 15A Shows the axial chromatic aberration curve of the optical imaging system of Example 7, which represents the deviation of the convergence focal points of light rays of different wavelengths after passing through the lens. Figure 15BThe astigmatism curve of the optical imaging system of Embodiment 7 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 15C The distortion curve of the optical imaging system of Embodiment 7 is shown, which represents the distortion magnitude values corresponding to different image heights. Figure 15D The longitudinal chromatic aberration curve of the optical imaging system of Embodiment 7 is shown, which represents the deviation of different image heights on the imaging plane after the light passes through the lens. Figure 22G The modulation transfer function curve (Modulation Transfer Function, MTF) of the optical imaging system of Embodiment 7 is shown, which represents the change of the modulation degree with respect to the spatial frequency. According to Figures 15A to 15D and Figure 22G it can be known that the optical imaging system given in Embodiment 7 can achieve good imaging quality.

[0167] Example 8

[0168] The following refers to Figures 16 to 17D the optical imaging system according to Embodiment 8 of the present application is described. Figure 16 The structural schematic diagram of the optical imaging system according to Embodiment 8 of the present application is shown.

[0169] As Figure 16 shown, the optical imaging system sequentially includes, from the object side to the image side along the second optical axis: a first prism L1, a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0170] The first prism L1 includes an incident surface S1, a reflection surface S2, and an exit surface S3. The first lens E1 has a positive optical power, with its object side surface S4 being convex and its image side surface S5 being concave. The second lens E2 has a negative optical power, with its object side surface S6 being convex and its image side surface S7 being concave. The third lens E3 has a negative optical power, with its object side surface S8 being convex and its image side surface S9 being concave. The fourth lens E4 has a positive optical power, with its object side surface S10 being convex and its image side surface S11 being convex. The fifth lens E5 has a negative optical power, with its object side surface S12 being concave and its image side surface S13 being convex. The sixth lens E6 has a negative optical power, with its object side surface S14 being concave and its image side surface S15 being concave. The seventh lens E7 has a negative optical power, with its object side surface S16 being convex and its image side surface S17 being concave. The second prism L2 includes an incident surface S18, a reflection surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. Light from an object travels along a first optical axis through the incident surface S1 of the first prism L1, is refracted by the reflection surface S2 of the first prism L1 to travel along a second optical axis, then sequentially passes through the surfaces S3 to S18, is refracted by the reflection surface S19 of the second prism L2 to travel along a third optical axis, then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0171] In Embodiment 8, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the value of the on-axis distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 13.59 mm, the value of half of the diagonal length of the effective pixel region on the imaging surface S23, ImgH, is 3.65 mm, and the value of the maximum field of view FOV is 16.7°.

[0172] Table 15 shows the basic parameter table of the optical imaging system of Embodiment 8, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm). Table 16 shows the higher-order term coefficients that can be used for each aspherical mirror surface in Embodiment 8, where each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1.

[0173]

[0174] Table 15

[0175]

[0176]

[0177] Table 16

[0178] Figure 17AShows the axial chromatic aberration curve of the optical imaging system of Embodiment 8, which represents the deviation of the convergence focal points of light rays of different wavelengths after passing through the lens. Figure 17B Shows the astigmatism curve of the optical imaging system of Embodiment 8, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane. Figure 17C Shows the distortion curve of the optical imaging system of Embodiment 8, which represents the distortion magnitude values corresponding to different image heights. Figure 17D Shows the lateral chromatic aberration curve of the optical imaging system of Embodiment 8, which represents the deviation of different image heights on the imaging plane after the light rays pass through the lens. Figure 22H Shows the modulation transfer function curve (Modulation Transfer Function, MTF) of the optical imaging system of Embodiment 8, which represents the change of the modulation degree with respect to the spatial frequency. According to Figures 17A to 17D and Figure 22H it can be seen that the optical imaging system given in Embodiment 8 can achieve good imaging quality.

[0179] Example 9

[0180] The following refers to Figures 18 to 19D describes the optical imaging system according to Embodiment 9 of the present application. Figure 18 Shows a schematic structural diagram of the optical imaging system according to Embodiment 9 of the present application.

[0181] As Figure 18 shown, the optical imaging system sequentially includes, along the second optical axis from the object side to the image side: a first prism L1, a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0182] The first prism L1 includes an incident surface S1, a reflecting surface S2, and an exit surface S3. The first lens E1 has a positive optical power, its object side surface S4 is convex, and its image side surface S5 is concave. The second lens E2 has a negative optical power, its object side surface S6 is convex, and its image side surface S7 is concave. The third lens E3 has a negative optical power, its object side surface S8 is convex, and its image side surface S9 is concave. The fourth lens E4 has a positive optical power, its object side surface S10 is convex, and its image side surface S11 is convex. The fifth lens E5 has a positive optical power, its object side surface S12 is concave, and its image side surface S13 is convex. The sixth lens E6 has a negative optical power, its object side surface S14 is concave, and its image side surface S15 is concave. The seventh lens E7 has a negative optical power, its object side surface S16 is convex, and its image side surface S17 is concave. The second prism L2 includes an incident surface S18, a reflecting surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. Light from an object travels along a first optical axis through the incident surface S1 of the first prism L1, is refracted by the reflecting surface S2 of the first prism L1 to travel along a second optical axis, then sequentially passes through the surfaces S3 to S18, is refracted by the reflecting surface S19 of the second prism L2 to travel along a third optical axis, then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0183] In Embodiment 9, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the value of the on-axis distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 14.12 mm, the value of half of the diagonal length ImgH of the effective pixel region on the imaging surface S23 is 3.65 mm, and the value of the maximum field of view FOV is 16.7°.

[0184] Table 17 shows the basic parameter table of the optical imaging system of Embodiment 9, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm). Table 18 shows the higher-order term coefficients that can be used for each aspherical mirror surface in Embodiment 9, where each aspherical surface type can be defined by the formula (1) given in Embodiment 1 above.

[0185]

[0186]

[0187] Table 17

[0188] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S4 -1.0309E-02 7.6631E-03 -2.3895E-04 2.0958E-04 1.6181E-04 2.9329E-06 2.2444E-05 -4.6550E-06 -7.5663E-07 S5 -1.5242E-01 2.2282E-02 -4.6235E-03 1.8794E-03 3.4085E-04 3.6473E-04 1.5418E-04 1.7170E-04 5.2643E-05 S6 4.9398E-02 -4.3727E-03 -3.1871E-04 7.2557E-04 4.9909E-05 5.4864E-04 2.1765E-05 2.2633E-04 2.3976E-05 S7 7.9231E-02 -4.8699E-03 -4.1604E-04 4.5649E-04 -3.9805E-05 3.2104E-04 -1.3232E-04 8.1677E-05 -2.3923E-05 S8 -1.5037E-01 2.1598E-02 -4.5492E-03 3.1194E-03 1.3141E-04 -1.3715E-04 -1.7688E-04 -9.5963E-05 -3.2269E-05 S9 1.7730E-02 -1.0799E-02 5.2726E-03 -7.3246E-05 6.5299E-04 -6.2077E-04 -4.1120E-04 -4.3934E-04 -8.2794E-05 S10 1.2859E-02 -6.7530E-03 2.0079E-03 -1.5882E-03 1.4842E-03 2.9822E-04 -7.1544E-05 -2.9223E-04 -7.9680E-05 S11 -5.4679E-02 2.1575E-02 -4.5168E-03 1.3309E-03 5.9022E-04 3.9918E-04 -9.3126E-06 -7.2807E-05 -3.6504E-05 S12 2.3488E-01 -9.8446E-03 4.4883E-03 2.9928E-03 -6.4217E-04 2.9691E-04 -3.2856E-06 -4.5053E-05 -2.4508E-05 S13 1.9052E-01 -1.7082E-02 3.6479E-03 2.7849E-03 -4.6216E-04 5.1589E-04 8.0753E-05 -1.5752E-05 -4.1496E-05 S14 4.7849E-03 3.1899E-02 -8.4772E-03 1.3019E-03 2.8514E-04 1.7048E-04 2.1631E-04 9.6805E-05 -1.1965E-05 S15 2.5766E-01 4.4027E-02 -7.1941E-03 -4.5675E-05 -5.1794E-04 -2.9651E-04 1.3205E-04 6.8931E-05 -8.7153E-06 S16 7.9641E-01 -1.9435E-02 -3.1931E-03 -3.1150E-03 -1.5976E-03 -4.2815E-04 4.7828E-05 8.6467E-05 7.8870E-06 S17 5.8402E-01 -5.4292E-02 2.9715E-04 -1.7895E-03 -7.5085E-04 -2.0769E-04 -6.3562E-05 -2.9258E-05 -2.3578E-05

[0189] Table 18

[0190] Figure 19AThe axial chromatic aberration curve of the optical imaging system of Embodiment 9 is shown, which represents the deviation of the converging focal points of light rays with different wavelengths after passing through the lens. Figure 19B The astigmatism curve of the optical imaging system of Embodiment 9 is shown, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane. Figure 19C The distortion curve of the optical imaging system of Embodiment 9 is shown, which represents the distortion magnitude values corresponding to different image heights. Figure 19D The longitudinal chromatic aberration curve of the optical imaging system of Embodiment 9 is shown, which represents the deviation of different image heights on the imaging plane after the light rays pass through the lens. Figure 22I The modulation transfer function curve (Modulation Transfer Function, MTF) of the optical imaging system of Embodiment 9 is shown, which represents the change of the modulation degree with respect to the spatial frequency. According to Figures 19A to 19D and Figure 22I it can be known that the optical imaging system given in Embodiment 9 can achieve good imaging quality.

[0191] Example 10

[0192] The following refers to Figures 20 to 21D and describes the optical imaging system according to Embodiment 10 of the present application. Figure 20 The structural schematic diagram of the optical imaging system according to Embodiment 10 of the present application is shown.

[0193] As Figure 20 shown, the optical imaging system sequentially includes, from the object side to the image side along the second optical axis: a first prism L1, a diaphragm STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a second prism L2, and a filter E8. The first prism L1 is the first refractive optical element in the first imaging lens group, and the second prism L2 is the second refractive optical element in the second imaging lens group.

[0194] The first prism L1 includes an incident surface S1, a reflection surface S2, and an exit surface S3. The first lens E1 has a positive optical power, with its object side surface S4 being convex and its image side surface S5 being concave. The second lens E2 has a negative optical power, with its object side surface S6 being convex and its image side surface S7 being concave. The third lens E3 has a negative optical power, with its object side surface S8 being convex and its image side surface S9 being concave. The fourth lens E4 has a positive optical power, with its object side surface S10 being convex and its image side surface S11 being convex. The fifth lens E5 has a positive optical power, with its object side surface S12 being convex and its image side surface S13 being convex. The sixth lens E6 has a negative optical power, with its object side surface S14 being concave and its image side surface S15 being concave. The seventh lens E7 has a negative optical power, with its object side surface S16 being convex and its image side surface S17 being concave. The second prism L2 includes an incident surface S18, a reflection surface S19, and an exit surface S20. The filter E8 has an object side surface S21 and an image side surface S22. The optical imaging system has an imaging surface S23. Light from an object travels along a first optical axis through the incident surface S1 of the first prism L1, is refracted by the reflection surface S2 of the first prism L1 to travel along a second optical axis, then sequentially passes through the surfaces S3 to S18, is refracted by the reflection surface S19 of the second prism L2 to travel along a third optical axis, then sequentially passes through the surfaces S20 to S21, and finally forms an image on the imaging surface S23.

[0195] In Embodiment 10, the value of the total effective focal length f of the optical imaging system is 24.90 mm, the value of the on-axis distance TTLz from the object side surface S1 of the first prism L1 to the imaging surface S23 in the direction of the first optical axis (or the normal direction of the imaging surface S23) is 13.99 mm, the value of half of the diagonal length of the effective pixel region on the imaging surface S23, ImgH, is 3.65 mm, and the value of the maximum field of view FOV is 16.7°.

[0196] Table 19 shows the basic parameter table of the optical imaging system of Embodiment 10, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm). Table 20 shows the higher-order term coefficients that can be used for each aspherical mirror surface in Embodiment 10, where each aspherical surface type can be defined by the formula (1) given in Embodiment 1 above.

[0197]

[0198]

[0199] Table 19

[0200] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S4 -7.1707E-03 7.5338E-03 -5.4690E-05 -3.2930E-05 -6.3922E-05 -1.4440E-04 -9.9177E-05 -6.2924E-05 -1.1445E-05 S5 -1.5064E-01 2.4246E-02 -3.1054E-03 2.5195E-03 6.5580E-04 4.5659E-04 3.6438E-04 2.7040E-04 1.1053E-04 S6 4.9831E-02 -4.7828E-03 3.6659E-04 1.4888E-03 4.4194E-04 6.9786E-04 3.7131E-04 3.0241E-04 3.3926E-05 S7 7.9758E-02 -5.9381E-03 -2.3776E-04 1.2862E-03 3.5454E-04 7.4833E-04 3.2708E-04 2.1274E-04 -6.5676E-05 S8 -1.5241E-01 1.9529E-02 -5.2011E-03 2.6190E-03 -7.8094E-04 -3.3617E-04 -1.0571E-04 1.0983E-05 -2.0859E-05 S9 1.8956E-02 -1.0618E-02 4.2533E-03 5.9042E-05 2.5124E-04 -8.3788E-04 -4.1313E-04 -9.8086E-05 2.2466E-04 S10 1.2007E-02 -6.1423E-03 2.0646E-03 -1.7147E-03 2.0996E-03 2.1510E-04 -1.6192E-04 -1.5309E-04 1.5048E-04 S11 -5.6466E-02 2.1179E-02 -3.8977E-03 6.4186E-04 1.5328E-03 1.7345E-04 -8.7393E-05 -3.0305E-05 3.5304E-05 S12 2.2696E-01 -7.8502E-03 4.8319E-03 2.1275E-03 -5.2240E-05 -1.1037E-04 -7.4323E-06 -5.5764E-05 -1.3056E-05 S13 1.9620E-01 -1.5442E-02 3.7593E-03 1.5660E-03 3.7591E-05 4.7818E-05 1.0764E-04 -5.4917E-05 -2.6408E-05 S14 -1.5300E-02 3.0723E-02 -9.2226E-03 6.7833E-04 8.4767E-04 2.4262E-04 3.1341E-05 -6.7449E-05 -4.5773E-05 S15 2.5580E-01 4.6155E-02 -5.5932E-03 2.7083E-04 3.4194E-04 -2.9520E-04 -1.3569E-04 2.4751E-05 -9.9002E-06 S16 7.8836E-01 -1.9571E-02 -5.5140E-04 -1.2357E-03 -5.0029E-04 -5.3490E-04 -2.6835E-04 -4.9014E-06 3.4622E-07 S17 5.4720E-01 -5.2478E-02 1.4863E-03 -8.9455E-04 -5.5039E-04 -3.3484E-04 -9.8935E-05 9.3598E-07 -1.9921E-05

[0201] Table 20

[0202] Figure 21AThe axial chromatic aberration curve of the optical imaging system of Embodiment 10 is shown, which represents the deviation of the converging focal points of light rays with different wavelengths after passing through the lens. Figure 21B The astigmatism curve of the optical imaging system of Embodiment 10 is shown, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane. Figure 21C The distortion curve of the optical imaging system of Embodiment 10 is shown, which represents the distortion magnitude values corresponding to different image heights. Figure 21D The lateral chromatic aberration curve of the optical imaging system of Embodiment 10 is shown, which represents the deviation of different image heights on the imaging plane after the light rays pass through the lens. Figure 22J The modulation transfer function curve (Modulation Transfer Function, MTF) of the optical imaging system of Embodiment 10 is shown, which represents the change of the modulation degree with respect to the spatial frequency. According to Figures 21A to 21D and Figure 22J it can be known that the optical imaging system given in Embodiment 10 can achieve good imaging quality.

[0203] In summary, Embodiments 1 to 10 respectively satisfy the relationships shown in Table 21.

[0204] Conditional / Example 1 2 3 4 5 6 7 8 9 10 TTLz / f 0.55 0.56 0.56 0.55 0.54 0.55 0.55 0.55 0.57 0.56 |Dist| 0.02 0.01 0.03 0.01 0.06 0.02 0.02 0.04 0.01 0.01 f1 / f4 0.44 0.40 0.80 0.40 0.40 0.41 0.35 0.47 0.44 0.43 (f2 + f6) / f7 0.88 0.81 0.78 0.84 1.46 1.22 0.90 0.96 0.83 0.76 R1 / (R3 - R4) 0.86 0.57 0.65 0.92 0.85 0.85 0.88 0.98 0.84 0.97 R6 / R7 0.82 0.76 0.92 1.22 1.03 0.97 0.82 0.95 0.84 0.87 R14 / f 0.69 0.37 0.48 0.45 0.51 0.82 0.55 0.54 0.54 0.36 ΣCT / PL1 0.70 0.83 0.77 0.76 0.73 0.71 0.70 0.71 0.70 0.82 ΣAT / PL2 0.66 0.52 0.62 0.61 0.63 0.68 0.67 0.67 0.62 0.53 CT6 / (CT1 + CT7) 0.51 0.45 0.52 0.53 0.44 0.47 0.48 0.26 0.44 0.52 (CT4 + CT5) / T45 0.79 1.25 1.03 0.95 0.85 0.80 0.79 1.45 0.79 1.19 f / EPD 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.80

[0205] Table 21

[0206] This application also provides an imaging device, which is provided with an electronic photosensitive element for imaging. The electronic photosensitive element can be a charge coupled device (CCD) or a complementary metal oxide semiconductor element (CMOS). The imaging device can be an independent imaging device such as a digital camera, or an imaging module integrated on a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging system described above.

[0207] The above description is only for the preferred embodiments of this application and the explanation of the applied technical principles. Those skilled in the art should understand that the protection scope involved in this application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of this application. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) having similar functions disclosed in this application.

Claims

1. An optical imaging system, characterized in that, It has a first optical axis, a second optical axis perpendicular to the first optical axis, and a third optical axis perpendicular to the second optical axis. Among them, the first optical axis and the third optical axis are parallel. The optical imaging system includes: A first imaging lens group arranged along the first optical axis, including a first refractive optical element configured to deflect light incident in the direction of the first optical axis to propagate in the direction of the second optical axis; A second imaging lens group arranged along the second optical axis from the object side to the image side in sequence includes: a first lens with positive optical power, a second lens with negative optical power, a third lens, a fourth lens with positive optical power, a fifth lens, a sixth lens with negative optical power, and a seventh lens with negative optical power; the signs of the optical powers of the third lens and the fifth lens are the same; or, the third lens has negative optical power and the fifth lens has positive optical power; the object side surface of the first lens is convex; the object side surface of the second lens is convex and the image side surface is concave; the image side surface of the third lens is concave; the object side surface of the fourth lens is convex; the image side surface of the seventh lens is concave; and A third imaging lens group arranged along the third optical axis, including a second refractive optical element configured to deflect light incident in the direction of the second optical axis to propagate in the direction of the third optical axis; Among them, the number of lenses with optical power in the optical imaging system is seven; The distance TTLz from the object side end of the first imaging lens group to the imaging surface of the optical imaging system in the direction parallel to the third optical axis and the total effective focal length f of the optical imaging system satisfy: 0.51 < TTLz / f < 0.59; The effective focal length f2 of the second lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: 0.75 < (f2 + f6) / f7 ≤ 1.46; The curvature radius R1 of the object side surface of the first lens, the curvature radius R3 of the object side surface of the second lens, and the curvature radius R4 of the image side surface of the second lens satisfy: 0.55 < R1 / (R3 - R4) < 1.

00.

2. The optical imaging system according to claim 1, wherein The optical distortion Dist of the optical imaging system satisfies: |Dist| < 0.1%; 3. The optical imaging system according to claim 1, wherein The effective focal length f1 of the first lens and the effective focal length f4 of the fourth lens satisfy: 0.33 < f1 / f4 < 0.

82.

4. The optical imaging system according to claim 1, characterized in that, The first refractive optical element is a first prism, and the second refractive optical element is a second prism.

5. The optical imaging system according to claim 4, characterized in that, The sum ∑CT of the thicknesses of any lens among the first lens to the seventh lens on the second optical axis and the sum PL1 of the thickness of the first prism on the first optical axis and the thickness of the first prism on the second optical axis satisfy: 0.66 < ∑CT / PL1 < 0.

85.

6. The optical imaging system according to claim 4, characterized in that, The sum ∑AT of the spacing distances of any two adjacent lenses among the first lens to the seventh lens on the second optical axis and the sum PL2 of the thickness of the second prism on the second optical axis and the thickness of the second prism on the third optical axis satisfy: 0.50 < ∑AT / PL2 < 0.

70.

7. The optical imaging system according to claim 1, wherein The radius of curvature R6 of the image side of the third lens and the radius of curvature R7 of the object side of the fourth lens satisfy: 0.76 ≤ R6 / R7 < 1.

25.

8. The optical imaging system according to claim 1, wherein The radius of curvature R14 of the image side of the seventh lens and the total effective focal length f of the optical imaging system satisfy: 0.35 < R14 / f < 0.

85.

9. The optical imaging system according to claim 1, wherein The central thickness CT1 of the first lens on the second optical axis, the central thickness CT6 of the sixth lens on the second optical axis, and the central thickness CT7 of the seventh lens on the second optical axis satisfy: 0.24 < CT6 / (CT1 + CT7) < 0.

55.

10. The optical imaging system according to claim 1, characterized in that, The central thickness CT4 of the fourth lens on the second optical axis, the central thickness CT5 of the fifth lens on the second optical axis, and the spacing distance T45 between the fourth lens and the fifth lens on the second optical axis satisfy: 0.78 < (CT4 + CT5) / T45 < 1.47.

Images