Optical image capturing system

Abstract

The invention discloses an optical imaging system, which sequentially comprises an imaging lens group, a prism and an imaging surface from an object side to an image side along an optical axis, and the imaging lens group sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power and a fifth lens with negative focal power from the object side to the image side along the optical axis, the object side surface of the second lens is a convex surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the fourth lens has positive focal power, and the object side surface of the fourth lens is a convex surface; wherein the optical imaging system comprises four lenses with focal power; the imaging lens group and the imaging surface are positioned on the same side of the prism, and the maximum field angle FOV of the optical imaging system is greater than or equal to 23.2 degrees and less than or equal to 23.6 degrees; the central thickness CT1 of the first lens on the optical axis and the central thickness CT2 of the second lens on the optical axis meet the following conditions: 1.35 lt; cT2 / CT1lt; and 2.60.

Description

Technical Field

[0001] The present invention relates to the field of optical devices, and particularly to an optical imaging system. Background Art

[0002] With the continuous development of portable devices such as smart phones, the technology of camera lenses is also constantly advancing. Telephoto lenses have been widely used due to their advantages such as clear imaging of distant objects and large magnification ratios.

[0003] In recent years, electronic products have put forward higher and higher requirements for thinness and lightness. At the same time, the telephoto lenses to be mounted on them need to be able to achieve imaging of distant objects while ensuring the thinness of the lenses. However, traditional telephoto lenses are difficult to meet the requirements of high specifications and thinness at the same time, and traditional periscope telephoto lenses also sacrifice part of the distance between lenses when applied to portable devices due to their too large volume. Therefore, how to make the camera lens have a longer focal length while ensuring miniaturization is one of the problems to be solved in the industry currently. Summary of the Invention

[0004] On the one hand, the present application provides such an optical imaging system, which sequentially includes an imaging lens group, a prism, and an imaging surface along the optical axis from the object side to the image side. The imaging lens group sequentially includes along the optical axis from the object side to the image side: a first lens with a negative optical power, whose object side surface is convex and image side surface is concave; a second lens with a positive optical power, whose object side surface is convex; a third lens with a negative optical power, whose object side surface is convex and image side surface is concave; and a fourth lens with a positive optical power, whose object side surface is convex. The imaging lens group and the imaging surface are located on the same side of the prism. The maximum field of view FOV of the optical imaging system satisfies: 23.2° ≤ FOV ≤ 23.6°. The central thickness CT1 of the first lens on the optical axis and the central thickness CT2 of the second lens on the optical axis satisfy: 1.35 < CT2 / CT1 < 2.6.

[0005] According to an exemplary embodiment of the present application, the first lens is a glass lens; the refractive index N1 of the first lens and the refractive index N2 of the second lens satisfy: 1.1 < N1 / N2 < 1.2.

[0006] According to an exemplary embodiment of the present application, the total effective focal length f of the optical imaging system and the effective focal length f3 of the third lens satisfy: -2.5 ≤ f / f3 < -1.35.

[0007] According to an exemplary embodiment of the present application, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 1.1 < R1 / R2 < 1.2; the Abbe number V1 of the first lens and the effective focal length f1 of the first lens satisfy: -5.1 mm < f1 / V1 < -3.3 mm.

[0008] According to an exemplary embodiment of the present application, the total effective focal length f of the optical imaging system and the effective focal length f1 of the first lens satisfy: -9.55 < f1 / f < -9.3.

[0009] According to an exemplary embodiment of the present application, the central thickness CT1 of the first lens on the optical axis and the edge thickness ET1 at the maximum effective radius of the first lens satisfy: 1.1 ≤ CT1 / ET1 ≤ 1.2.

[0010] According to an exemplary embodiment of the present application, the effective focal length f2 of the second lens, the total effective focal length f of the optical imaging system, and the curvature radius R3 of the object side surface of the second lens satisfy: 0.3 < f2 / f < 0.7 and 1.2 < f2 / R3 < 2.5.

[0011] According to an exemplary embodiment of the present application, the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the object side surface of the third lens satisfy: 0.05 < R6 / R5 < 0.65.

[0012] According to an exemplary embodiment of the present application, the effective focal length f4 of the fourth lens and the effective focal length f3 of the third lens satisfy: -13.25 < f4 / f3 < -1.25.

[0013] According to an exemplary embodiment of the present application, the central thickness CT2 of the second lens on the optical axis, the axial spacing distance T23 between the second lens and the third lens on the optical axis, and the central thickness CT3 of the third lens on the optical axis satisfy: 2.2 < CT2 / (T23 + CT3) < 4.9.

[0014] According to an exemplary embodiment of the present application, the effective focal length f3 of the third lens, the curvature radius R6 of the image side surface of the third lens, and the refractive index N3 of the third lens satisfy: -8.4 < f3 / R6 × N3 < -2.85.

[0015] According to an exemplary embodiment of the present application, the axial spacing distance T12 between the first lens and the second lens on the optical axis and the axial spacing distance T23 between the second lens and the third lens on the optical axis satisfy: 2.1 < T12 / T23 < 3.25.

[0016] According to an exemplary embodiment of the present application, the number of lenses in the imaging lens group with an Abbe number greater than 50 is equal to the number of lenses in the imaging lens group with an Abbe number less than 50.

[0017] According to an exemplary embodiment of the present application, the axial distance SAG32 between the intersection of the image side surface of the third lens and the optical axis and the vertex of the effective radius of the image side surface of the third lens and the axial spacing distance T34 between the third lens and the fourth lens on the optical axis satisfy: 0.95 < SAG32 / T34 < 15.8.

[0018] According to an exemplary embodiment of the present application, the optical imaging system further includes a diaphragm. The on-axis distance SL from the diaphragm to the imaging surface and the on-axis distance TD from the object side surface of the first lens to the image side surface of the fourth lens satisfy: 1.3 < SL / TD < 1.5.

[0019] According to an exemplary embodiment of the present application, the prism is a trapezoidal prism. The trapezoidal prism includes a first surface and a second surface that are arranged opposite to each other and parallel to each other. The first surface has an incident area and an exit area that are spaced apart. The light passing through the imaging lens group enters the trapezoidal prism from the incident area, and after multiple reflections in the trapezoidal prism, exits from the exit area to the imaging surface.

[0020] By using a rear prism in the optical imaging system of the present application and placing the imaging lens group and the imaging surface on one side of the prism, a turning configuration of the optical axis is achieved, which is beneficial to reducing the thickness of the optical imaging system and increasing the flexibility of the spatial configuration. It is also beneficial to exhibit long focal length characteristics while ensuring that the optical imaging system has a sufficient total optical length. Further, the maximum field of view angle of the optical imaging system of the present application is controlled within a certain range, which is beneficial to the optical imaging system to achieve a longer focal length within a certain imaging effective pixel area, and thus achieve the long focal length characteristics of the optical imaging system. Reasonably distributing the central thickness of the first lens and the second lens is beneficial to each lens having sufficient spacing distance and higher surface freedom, and thus is beneficial to improving the correction ability of the optical imaging system for field curvature and astigmatism. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0022] Figure 1 Shows a schematic optical path turning diagram of the optical imaging system according to the present application;

[0023] Figure 2 Shows a schematic structural diagram of the optical imaging system according to Embodiment 1 of the present application;

[0024] Figure 3 、 Figure 4 and Figure 5 Respectively show the astigmatism curve, distortion curve, and relative illumination curve of the optical imaging system according to Embodiment 1 of the present application;

[0025] Figure 6 Shows a schematic structural diagram of the optical imaging system according to Embodiment 2 of the present application;

[0026] Figure 7 、 Figure 8 and Figure 9The astigmatism curve, distortion curve and relative illumination curve of the optical imaging system of Example 2 of the present application are respectively shown;

[0027] Figure 10 A schematic structural diagram of an optical imaging system according to Embodiment 3 of the present application is shown;

[0028] Figure 11 , Figure 12 and Figure 13 The astigmatism curve, distortion curve and relative illumination curve of the optical imaging system of Example 3 of the present application are respectively shown;

[0029] Figure 14 A schematic structural diagram of an optical imaging system according to Embodiment 4 of the present application is shown;

[0030] Figure 15 , Figure 16 and Figure 17 The astigmatism curve, distortion curve and relative illumination curve of the optical imaging system of Example 4 of the present application are respectively shown;

[0031] Figure 18 A schematic structural diagram of an optical imaging system according to Embodiment 5 of the present application is shown;

[0032] Figure 19 , Figure 20 and Figure 21 The astigmatism curve, distortion curve and relative illumination curve of the optical imaging system of Example 5 of the present application are respectively shown;

[0033] Figure 22 A schematic structural diagram of an optical imaging system according to Embodiment 6 of the present application is shown;

[0034] Figure 23 , Figure 24 and Figure 25 The astigmatism curve, distortion curve and relative illumination curve of the optical imaging system of Example 6 of the present application are respectively shown. DETAILED DESCRIPTION

[0035] In order to better understand the present application, various aspects of the present application are described in detail 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.

[0036] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0037] In the drawings, for the sake of clarity, the thickness, dimensions, and shape of the lenses have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are presented by way of example. That is, the spherical or aspherical shapes are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn to an exact scale.

[0038] In this document, 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 being 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.

[0039] It should also be understood that the terms "comprises," "comprising," "has," "including," and / or "including having," 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. In addition, when describing the 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.

[0040] Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms should be interpreted to have 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.

[0041] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments may be combined with each other. The following will describe this application in detail with reference to the drawings and in conjunction with the embodiments.

[0042] Referring to Figure 1 , the present application provides an optical imaging system. The optical imaging system sequentially includes an imaging lens group G, a prism T, and an imaging surface S11 along the optical axis from the object side to the image side. The imaging lens group G and the imaging surface S11 are located on the same side of the prism T. By providing a prism and placing the imaging lens group and the imaging surface on one side of the prism, a turning configuration of the optical axis is achieved, which is beneficial for reducing the volume of the imaging system.

[0043] In an exemplary embodiment, the prism T may have a first surface 110, a second surface 120, a third surface 130, and a fourth surface 140. The first surface 110 and the second surface 120 are arranged opposite to each other. The third surface 130 and the fourth surface 140 are arranged opposite to each other, and the third surface 130 and the fourth surface 140 are each located between the first surface 110 and the second surface 120 and connect the first surface 110 and the second surface 120.

[0044] The first surface 110 has an incident region 111 and an exit region 112, and the incident region 111 and the exit region 112 are spaced apart from each other by a certain distance. As an example, the optical path may be turned three times by the prism, and the angle between each optical axis may be adjusted as needed. For example, the light incident on the prism T may enter the prism through the incident region 111 of the first surface 110, and after being reflected three times by the third surface 130, the first surface 110, and the fourth surface 140, it leaves the prism from the exit region 112 of the first surface 110. During this process, the optical path passes through the incident region 111 of the first surface 110 to the third surface 130 along the first optical axis, the third surface 130 turns the optical path from the first optical axis to the second optical axis, the first surface 110 turns the optical path from the second optical axis to the third optical axis, the fourth surface 140 turns the optical path from the third optical axis to the fourth optical axis, and then the optical path passes through the exit region 112 of the first surface 110 to the imaging surface S11 along the fourth optical axis. It should be understood that the three reflections of the light in the prism are exemplary, and according to the specific optical path requirements, more reflections of the light in the prism can be achieved by changing the prism settings.

[0045] In an exemplary embodiment, the third surface 130 and the fourth surface 140 may be mirrors or surfaces with a reflective coating to turn the optical path by specular reflection. The first surface 110 may use the principle of total internal reflection to turn the optical path. As an example, the prism T may be a trapezoidal prism, whose first surface 110 and second surface 120 are substantially parallel to each other, and the aperture of the first surface 110 may be smaller than the aperture of the second surface 120 of the prism. Optionally, the prism T may be an integrally formed trapezoidal prism, and there are no other reflective or refractive surfaces between the first surface 110, the second surface 120, the third surface 130, and the fourth surface 140.

[0046] In an exemplary embodiment, the imaging lens group G may sequentially include a first lens, a second lens, a third lens, and a fourth lens along the optical axis from the object side to the image side. The number of lenses with positive optical power and the number of lenses with negative optical power in the imaging lens group may be equal.

[0047] In an exemplary embodiment, the first lens may have a negative optical power. Optionally, the first lens may be a glass lens. The Abbe number V1 of the first lens and the effective focal length f1 of the first lens may satisfy: -5.1 mm < f1 / V1 < -3.3 mm. When the first lens uses a glass material with a relatively high Abbe number, reasonably configuring the relationship between the effective focal length of the first lens and the Abbe number of the first lens helps to improve the chromatic aberration correction ability of the optical imaging system.

[0048] In an exemplary embodiment, the total effective focal length f of the optical imaging system and the effective focal length f1 of the first lens may satisfy: -9.55 < f1 / f < -9.3. By reasonably controlling the ratio of the effective focal length of the first lens to the total effective focal length of the imaging system, it is possible to effectively avoid excessive deflection of light rays, and at the same time effectively balance aberrations and improve the imaging quality of the optical imaging system.

[0049] In an exemplary embodiment, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens may satisfy: 1.1 < R1 / R2 < 1.2. By controlling the ratio of the radius of curvature of the object side surface of the first lens to the radius of curvature of the image side surface of the first lens within a certain range, it is possible to effectively reduce the processing difficulty of the lens and improve the yield of lens processing. As an example, the object side surface of the first lens is a convex surface and the image side surface is a concave surface.

[0050] In an exemplary embodiment, the central thickness CT1 of the first lens on the optical axis and the edge thickness ET1 at the maximum effective radius of the first lens may satisfy: 1.1 ≤ CT1 / ET1 ≤ 1.2. Reasonably configuring the ratio of the central thickness of the first lens on the optical axis to the edge thickness at the maximum effective radius of the first lens is beneficial to improving the processability of the lens, reducing the difficulty of lens injection molding, and ensuring that the optical imaging system has good imaging quality.

[0051] In an exemplary embodiment, the second lens may have a positive optical power. The effective focal length f2 of the second lens and the total effective focal length f of the optical imaging system may satisfy: 0.3 < f2 / f < 0.7. Reasonably controlling the ratio of the effective focal length of the second lens to the total effective focal length of the optical imaging system is beneficial to improving chromatic aberration, and can effectively adjust the position of light ray focusing, and enhance the light converging ability of the optical imaging system.

[0052] In an exemplary embodiment, the effective focal length f2 of the second lens and the radius of curvature R3 of the object side surface of the second lens may satisfy: 1.2 < f2 / R3 < 2.5. Reasonably controlling the ratio of the effective focal length of the second lens to the radius of curvature of the object side surface of the second lens is beneficial to improving the field curvature and distortion of the optical imaging system and reducing the processing difficulty of the second lens. As an example, the object side surface of the second lens may be a convex surface.

[0053] In an exemplary embodiment, the refractive index N1 of the first lens and the refractive index N2 of the second lens may satisfy: 1.1 < N1 / N2 < 1.2. Reasonably configuring the relationship between the refractive index of the first lens and the refractive index of the second lens is beneficial to improving the light converging ability of the optical imaging system and at the same time improving the ability of the optical imaging system to correct aberrations, thereby improving the imaging quality.

[0054] In an exemplary embodiment, the central thickness CT1 of the first lens on the optical axis and the central thickness CT2 of the second lens on the optical axis may satisfy: 1.35 < CT2 / CT1 < 2.6. Reasonably distributing the central thicknesses of the first lens and the second lens is beneficial for the lenses to have sufficient spacing distance and higher surface freedom, and at the same time is beneficial for enhancing the ability of the optical imaging system to correct field curvature and astigmatism.

[0055] In an exemplary embodiment, the third lens may have a negative optical power. The total effective focal length f of the optical imaging system and the effective focal length f3 of the third lens may satisfy: -2.5 ≤ f / f3 < -1.35. The third lens assumes a negative optical power, which is beneficial for the optical imaging system to balance aberrations and improve the resolution ability of the optical imaging system.

[0056] In an exemplary embodiment, the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens may satisfy: 0.05 < R6 / R5 < 0.65. Reasonably configuring the curvature radii of the object side surface and the image side surface of the third lens can effectively weaken the sensitivity of the optical imaging system, is beneficial for the optical imaging system to have a larger field of view angle, is beneficial for improving the resolution ability of the optical imaging system, and at the same time is beneficial for the optical imaging system to maintain good processability. As an example, the object side surface of the third lens may be a convex surface and the image side surface may be a concave surface.

[0057] In an exemplary embodiment, the effective focal length f3 of the third lens, the curvature radius R6 of the image side surface of the third lens and the refractive index N3 of the third lens may satisfy: -8.4 < f3 / R6 × N3 < -2.85. Reasonably configuring the relationship between the effective focal length of the third lens, the curvature radius of the image side surface of the third lens and the refractive index of the third lens can effectively correct the field curvature and distortion of the optical imaging system, and at the same time can effectively reduce the processing difficulty of the third lens.

[0058] In an exemplary embodiment, the distance T12 between the first lens and the second lens on the optical axis and the distance T23 between the second lens and the third lens on the optical axis may satisfy: 2.1 < T12 / T23 < 3.25. By controlling the ratio of the distance between the first lens and the second lens on the optical axis to the distance between the second lens and the third lens on the optical axis within a certain range, the ability of the optical imaging system to correct field curvature and astigmatism can be effectively improved, and at the same time, it is beneficial to realize the miniaturization of the optical imaging system.

[0059] In an exemplary embodiment, the central thickness CT2 of the second lens on the optical axis, the distance T23 between the second lens and the third lens on the optical axis, and the central thickness CT3 of the third lens on the optical axis may satisfy: 2.2 < CT2 / (T23 + CT3) < 4.9. Reasonably configuring the relationship between the central thickness of the second lens on the optical axis, the distance between the second lens and the third lens on the optical axis, and the central thickness of the third lens on the optical axis is beneficial to improving the assembly stability of the optical imaging system and the consistency of mass production of the optical imaging system.

[0060] In an exemplary embodiment, the third lens may have a negative optical power, and the fourth lens may have a positive optical power. The effective focal length f4 of the fourth lens and the effective focal length f3 of the third lens may satisfy: -13.25 < f4 / f3 < -1.25. By controlling the ratio of the effective focal length of the fourth lens to the effective focal length of the third lens within a certain range and configuring the third lens with a relatively large negative optical power, it is beneficial to correct chromatic aberration of the optical imaging system. At the same time, by configuring the fourth lens with a positive optical power, the exit pupil diameter of the fourth lens can be reduced.

[0061] In an exemplary embodiment, the axial distance SAG32 between the intersection point of the image side of the third lens and the optical axis and the vertex of the effective radius of the image side of the third lens and the distance T34 between the third lens and the fourth lens on the optical axis may satisfy: 0.95 < SAG32 / T34 < 15.8. By controlling the ratio of the axial distance between the intersection point of the image side of the third lens and the optical axis and the vertex of the effective radius of the image side of the third lens to the distance between the third lens and the fourth lens on the optical axis within a certain range, it is beneficial to control the bending degree of the third lens within a reasonable range, which is beneficial to achieving a smaller exit pupil diameter, thereby compressing the thickness of the rear prism and realizing the miniaturization of the optical imaging system.

[0062] In an exemplary embodiment, the optical imaging system may further include a diaphragm. The diaphragm may be disposed between the fourth lens and the prism. The on-axis distance SL from the diaphragm to the imaging surface and the on-axis distance TD from the object side surface of the first lens to the image side surface of the fourth lens may satisfy: 1.3 < SL / TD < 1.5. Reasonably configuring the relationship between the on-axis distance from the diaphragm to the imaging surface and the on-axis distance from the object side surface of the first lens to the image side surface of the fourth lens is beneficial to reducing the total length of the optical imaging system and realizing miniaturization of the optical imaging system.

[0063] In an exemplary embodiment, the number of lenses with an Abbe number greater than 50 in the imaging lens group is equal to the number of lenses with an Abbe number less than 50 in the imaging lens group. Reasonably allocating the number of high-Abbe-number lenses and low-Abbe-number lenses in the imaging lens group is beneficial to balancing the lateral chromatic aberration between lenses and is beneficial for the optical imaging system to obtain better imaging quality. As an example, the number of lenses with an Abbe number greater than 50 and the number of lenses with an Abbe number less than 50 in the imaging lens group may both be two. Preferably, the Abbe numbers of the first lens and the second lens are greater than 50, while the Abbe numbers of the third lens and the fourth lens are less than 50.

[0064] In an exemplary embodiment, the maximum field of view FOV of the optical imaging system may satisfy: 23.2° ≤ FOV ≤ 23.6°. Controlling the maximum field of view of the optical imaging system within a certain range is beneficial for the optical imaging system to achieve a longer focal length within a certain imaging effective pixel area, thereby realizing the telephoto characteristic of the optical imaging system. As an example, the total effective focal length f of the optical imaging system may satisfy 18.9mm ≤ f < 19.3mm.

[0065] On the other hand, the present application provides an optical imaging system including an imaging lens group, a prism, and an imaging surface, wherein the imaging lens group and the imaging surface are located on the same side of the prism. The imaging lens group sequentially includes, along the optical axis from the object side to the image side: a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a negative optical power, and a fourth lens with a positive optical power. The total effective focal length f of the optical imaging system, the effective focal length f1 of the first lens, and the effective focal length f3 of the third lens may satisfy: -9.55 < f1 / f < -9.3, and -2.5 ≤ f / f3 < -1.35.

[0066] 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 may be changed to obtain the various results and advantages described in this specification.

[0067] The following further describes specific embodiments of the optical imaging system applicable to the above embodiments with reference to the accompanying drawings.

[0068] Embodiment 1

[0069] Refer to the following Figure 2 and Figures 3 to 5 to describe the optical imaging system according to Embodiment 1 of the present application.

[0070] As Figure 2 shown, the optical imaging system sequentially includes an imaging lens group, a prism T, and an imaging surface along the optical axis from the object side to the image side. The imaging lens group includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0071] The first lens E1 has a negative optical power, its object surface S1 is convex, and its image surface S2 is concave; the second lens E2 has a positive optical power, its object surface S3 is convex, and its image surface S4 is convex; the third lens E3 has a negative optical power, its object surface S5 is convex, and its image surface S6 is concave; the fourth lens E4 has a positive optical power, its object surface S7 is convex, and its image surface S8 is concave.

[0072] The aperture stop STO is disposed between the fourth lens E4 and the prism T. A protective glass having an object surface S9 and an image surface S10 can be placed between the prism T and the imaging surface S11. Light from the object sequentially passes through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and is incident on the imaging surface S11 after being reflected multiple times (e.g., 3 times) inside the prism T.

[0073] 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).

[0074]

[0075]

[0076] Table 1

[0077] In this embodiment, the object surface and the image surface of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces, and the surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0078]

[0079] where xWhen the aspherical surface is at a position with a height of h along the optical axis, the sagitta is the distance from the vertex of the aspherical surface; c is the paraxial curvature of the aspherical surface, c = 1 / R (that is, the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); Ai is the correction coefficient of the i-th order of the aspherical surface. Table 2 gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 that can be used for each aspherical mirror S3 - S8 in Example 1.

[0080] Face number A4 A6 A8 A10 A12 A14 A16 S3 1.7815E-01 1.5274E-02 2.6709E-03 8.2664E-04 2.7268E-04 1.2674E-04 3.4106E-05 S4 -1.4839E-01 -4.7614E-03 -1.0395E-02 -4.4931E-03 1.3200E-03 -5.3388E-03 1.1200E-03 S5 -3.7907E-02 1.8200E-02 2.1651E-02 -2.1541E-03 5.8488E-03 -5.3785E-03 2.0345E-03 S6 -4.8583E-01 1.1636E-01 -2.9584E-02 7.0770E-03 -2.3880E-03 1.4191E-04 4.7107E-04 S7 1.8590E-01 -9.6758E-03 1.7487E-02 1.4333E-03 5.5232E-03 1.7230E-03 1.7207E-03 S8 1.7035E-01 -9.3962E-03 -7.7507E-04 -1.4191E-03 3.5048E-04 1.1544E-04 3.0094E-04 Face number A18 A20 A22 A24 A26 A28 A30 S3 2.4853E-05 -1.6276E-05 3.7101E-06 -2.6819E-06 -8.7648E-06 0.0000E+00 0.0000E+00 S4 -4.4125E-03 -5.5197E-04 -1.4706E-05 2.2019E-03 7.8159E-04 2.2417E-04 -3.3748E-04 S5 -4.7985E-03 -7.7999E-04 4.3082E-04 2.5511E-03 6.8692E-04 -6.4909E-05 -5.1933E-04 S6 -6.8471E-04 2.4842E-04 -1.4967E-04 2.0036E-04 -1.9653E-04 9.4636E-05 -1.6079E-05 S7 -6.9481E-04 -5.0963E-04 -2.2602E-04 -5.3884E-04 -4.3549E-04 -2.3765E-04 3.9881E-05 S8 -1.8981E-04 -9.2353E-05 -3.1878E-05 -1.1232E-04 -5.9893E-05 2.1741E-05 1.0179E-05

[0081] Table 2

[0082] Figure 3 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 corresponding to different field angles. Figure 4 Shows the distortion curve of the optical imaging system of Example 1, which represents the distortion magnitude values corresponding to different field angles. Figure 5 Shows the relative illumination curve of the optical imaging system of Example 1, which represents the relative illumination values corresponding to different field angles. According to Figures 3 to 5 It can be seen that the optical imaging system of Example 1 can achieve good imaging quality.

[0083] Example 2

[0084] The following refers to Figure 6 、 Figures 7 to 9 to describe the optical imaging system according to Embodiment 2 of the present application.

[0085] As Figure 6 shown, the optical imaging system includes, in order from the object side to the image side along the optical axis, an imaging lens group, a prism T, and an imaging surface. The imaging lens group includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0086] The first lens E1 has a negative optical power, its object side surface S1 is convex, and its image side surface S2 is concave; the second lens E2 has a positive optical power, its object side surface S3 is convex, and its image side surface S4 is convex; the third lens E3 has a negative optical power, its object side surface S5 is convex, and its image side surface S6 is concave; the fourth lens E4 has a positive optical power, its object side surface S7 is convex, and its image side surface S8 is convex.

[0087] The aperture stop STO is disposed between the fourth lens E4 and the prism T. A protective glass with an object side surface S9 and an image side surface S10 can be placed between the prism T and the imaging surface S11. Light from the object sequentially passes through the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, and is incident on the imaging surface S11 after multiple reflections (for example, 3 times) inside the prism T.

[0088] Table 3 shows the basic parameter table of the optical imaging system of Example 2, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0089]

[0090] Table 3

[0091] In this embodiment, the object side and the image side of any one of the second lens E2 to the fourth lens E4 are both aspherical surfaces. Table 4 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 of the aspherical mirror surfaces S3 - S8 that can be used in Example 2.

[0092] Face number A4 A6 A8 A10 A12 A14 A16 S3 1.7613E-01 1.6686E-02 3.9307E-03 5.8497E-04 1.2498E-04 6.1513E-05 -9.5431E-05 S4 9.8027E-02 1.3340E-02 -5.5269E-03 1.6579E-03 -4.4895E-04 -4.6138E-04 -7.7681E-04 S5 -4.6140E-01 8.5896E-02 -2.2580E-02 5.2831E-03 -5.4113E-04 -9.0793E-04 -5.9401E-04 S6 -4.4312E-01 6.0009E-02 -1.5121E-02 1.7720E-03 1.2858E-03 -6.0963E-04 -4.2758E-04 S7 6.2044E-02 1.5226E-02 -1.0160E-02 -1.0901E-04 1.6316E-03 -5.0152E-04 -2.9251E-04 S8 6.1609E-02 2.2178E-03 -5.7198E-03 -8.5501E-05 7.1763E-04 -2.0826E-04 5.0028E-05 Face number A18 A20 A22 A24 A26 A28 A30 S3 -4.1015E-05 -1.2406E-05 -2.1264E-06 -1.1965E-05 -5.8092E-06 0.0000E+00 0.0000E+00 S4 1.4106E-04 2.0559E-04 -8.9266E-06 -7.3867E-05 4.6102E-05 -1.6284E-05 -7.5404E-06 S5 -1.0463E-05 3.4099E-04 -6.2615E-06 -1.2124E-04 5.3788E-05 4.1957E-06 -7.8675E-06 S6 -5.7705E-04 -2.4124E-05 1.6753E-04 2.8753E-05 2.1710E-06 6.7611E-06 9.0434E-06 S7 -5.1212E-04 -4.5014E-05 2.0677E-04 4.2821E-05 -2.8308E-06 -3.1552E-06 1.4879E-05 S8 -1.5143E-04 1.0389E-05 8.0673E-05 1.1335E-05 -1.3628E-05 -6.1644E-07 3.4598E-06

[0093] Table 4

[0094] Figure 7 shows the astigmatism curve of the optical imaging system of Example 2, which represents the meridional image plane curvature and the sagittal image plane curvature corresponding to different field angles. Figure 8 shows the distortion curve of the optical imaging system of Example 2, which represents the distortion magnitude values corresponding to different field angles. Figure 9 shows the relative illumination curve of the optical imaging system of Example 2, which represents the relative illumination values corresponding to different field angles. According to Figures 7 to 9 it can be known that the optical imaging system of Example 2 can achieve good imaging quality.

[0095] Example 3

[0096] The following refers to Figure 10 、 Figures 11 to 13 to describe the optical imaging system according to Embodiment 3 of the present application.

[0097] As Figure 10 shown, the optical imaging system includes, in order from the object side to the image side along the optical axis, an imaging lens group, a prism T, and an imaging surface. The imaging lens group includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0098] The first lens E1 has a negative optical power, its object side S1 is a convex surface, and its image side S2 is a concave surface; the second lens E2 has a positive optical power, its object side S3 is a convex surface, and its image side S4 is a concave surface; the third lens E3 has a negative optical power, its object side S5 is a convex surface, and its image side S6 is a concave surface; the fourth lens E4 has a positive optical power, its object side S7 is a convex surface, and its image side S8 is a concave surface.

[0099] The aperture STO is disposed between the fourth lens E4 and the prism T. A protective glass having an object side S9 and an image side S10 can be placed between the prism T and the imaging surface S11. Light from the object sequentially passes through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and is incident on the imaging surface S11 after being reflected multiple times (e.g., 3 times) inside the prism T.

[0100] 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).

[0101]

[0102] Table 5

[0103] In this embodiment, the object side and the image side of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces. Table 6 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 of the aspherical mirror surfaces S3 - S8 that can be used in Embodiment 3.

[0104]

[0105]

[0106] Table 6

[0107] Figure 11 shows the astigmatism curve of the optical imaging system of Embodiment 3, which represents the meridional image plane curvature and the sagittal image plane curvature corresponding to different field angles. Figure 12 shows the distortion curve of the optical imaging system of Embodiment 3, which represents the distortion magnitude values corresponding to different field angles. Figure 13 shows the relative illumination curve of the optical imaging system of Embodiment 3, which represents the relative illumination values corresponding to different field angles. According to Figures 11 to 13 it can be seen that the optical imaging system of Embodiment 3 can achieve good imaging quality.

[0108] Embodiment 4

[0109] The following refers to Figure 14 、 Figures 15 to 17 to describe the optical imaging system according to Embodiment 4 of the present application.

[0110] As Figure 14 shown, the optical imaging system sequentially includes an imaging lens group, a prism T, and an imaging surface along the optical axis from the object side to the image side. The imaging lens group includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0111] The first lens E1 has a negative optical power, its object side S1 is convex, and its image side S2 is concave; the second lens E2 has a positive optical power, its object side S3 is convex, and its image side S4 is convex; the third lens E3 has a negative optical power, its object side S5 is convex, and its image side S6 is concave; the fourth lens E4 has a positive optical power, its object side S7 is convex, and its image side S8 is concave.

[0112] The aperture stop STO is disposed between the fourth lens E4 and the prism T. A protective glass having an object side S9 and an image side S10 can be placed between the prism T and the imaging surface S11. Light from the object sequentially passes through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and is incident on the imaging surface S11 after being reflected multiple times (e.g., 3 times) inside the prism T.

[0113] Table 7 shows the basic parameter table of the optical imaging system of Embodiment 4, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0114]

[0115]

[0116] Table 7

[0117] In this embodiment, the object side and the image side of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces. Table 8 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 of the aspherical mirror surfaces S3-S8 that can be used in Embodiment 4.

[0118] Face number A4 A6 A8 A10 A12 A14 A16 S3 1.4376E-01 1.4065E-02 2.8474E-03 5.9334E-04 1.9216E-04 1.0429E-04 4.0532E-05 S4 -8.6678E-03 2.2211E-02 -5.8415E-03 1.7939E-03 5.9795E-04 -4.4381E-04 3.7325E-04 S5 -2.6095E-01 6.1356E-02 -1.5921E-02 3.5739E-03 3.9219E-04 -6.2196E-04 4.0139E-04 S6 -3.9105E-01 8.4875E-02 -1.8825E-02 5.1482E-03 -4.5491E-04 -2.0203E-04 1.5935E-04 S7 -4.0498E-01 2.1356E-02 -1.3133E-02 2.9715E-03 -4.4669E-04 -1.1866E-04 4.7396E-05 S8 -8.8968E-02 -1.4273E-02 8.1268E-04 -1.6457E-04 1.0631E-04 -1.9802E-05 -3.1692E-05 Face number A18 A20 A22 A24 A26 A28 A30 S3 2.7401E-05 4.0140E-06 6.0240E-06 -6.2996E-06 -2.4391E-06 0.0000E+00 0.0000E+00 S4 -3.4922E-04 2.8665E-04 -1.0274E-04 -2.5111E-05 1.1495E-05 3.0495E-05 -3.1985E-05 S5 -4.4585E-04 3.4781E-04 -7.7145E-05 -4.8777E-05 1.1060E-06 5.5812E-05 -3.9456E-05 S6 -4.1201E-04 1.6844E-04 6.1482E-05 1.2676E-05 -6.1605E-05 6.3739E-05 -6.2200E-06 S7 -3.3286E-04 8.9049E-05 7.6515E-05 2.7084E-05 -4.7846E-05 4.5603E-05 3.7293E-06 S8 -7.1193E-05 -3.6019E-06 2.0152E-05 8.5026E-06 -8.5229E-06 8.6883E-06 1.8663E-06

[0119] Table 8

[0120] Figure 15 Shows the astigmatism curve of the optical imaging system of Embodiment 4, which represents the meridional image plane curvature and the sagittal image plane curvature corresponding to different field angles. Figure 16 Shows the distortion curve of the optical imaging system of Embodiment 4, which represents the distortion magnitude values corresponding to different field angles. Figure 17 Shows the relative illumination curve of the optical imaging system of Embodiment 4, which represents the relative illumination values corresponding to different field angles. According to Figures 15 to 17 It can be seen that the optical imaging system of Embodiment 4 can achieve good imaging quality.

[0121] Embodiment 5

[0122] The following is referred to Figure 18 、 Figures 19 to 21Describe the optical imaging system according to Embodiment 5 of the present application.

[0123] As Figure 18 shown, the optical imaging system sequentially includes an imaging lens group, a prism T, and an imaging surface along the optical axis from the object side to the image side. The imaging lens group includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0124] The first lens E1 has a negative optical power, its object surface S1 is convex, and its image surface S2 is concave; the second lens E2 has a positive optical power, its object surface S3 is convex, and its image surface S4 is concave; the third lens E3 has a negative optical power, its object surface S5 is convex, and its image surface S6 is concave; the fourth lens E4 has a positive optical power, its object surface S7 is convex, and its image surface S8 is convex.

[0125] The aperture stop STO is disposed between the fourth lens E4 and the prism T. A protective glass having an object surface S9 and an image surface S10 can be placed between the prism T and the imaging surface S11. Light from the object sequentially passes through the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, and is incident on the imaging surface S11 after being reflected multiple times (e.g., 3 times) inside the prism T.

[0126] Table 9 shows the basic parameter table of the optical imaging system of Embodiment 5, where the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0127]

[0128]

[0129] Table 9

[0130] In this embodiment, the object surface and the image surface of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces. Table 10 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 of the aspherical mirror surfaces S3 - S8 that can be used in Embodiment 5.

[0131] Face number A4 A6 A8 A10 A12 A14 A16 S3 1.9776E-01 1.5762E-02 7.4361E-03 4.5406E-04 1.1032E-04 -1.7640E-04 -2.7087E-04 S4 1.1041E-01 6.9666E-03 8.8033E-04 -1.4143E-03 5.1774E-04 -1.2558E-03 -6.1480E-04 S5 -3.4640E-01 6.0771E-02 -1.6605E-02 2.7666E-03 -1.0932E-04 -1.2278E-03 -4.6620E-04 S6 -4.2196E-01 6.8496E-02 -1.8750E-02 3.2515E-03 4.5546E-04 -4.6631E-04 -2.7543E-04 S7 -1.3874E-01 4.8250E-02 -1.8116E-02 2.2579E-03 9.9889E-04 -4.9195E-04 -2.0570E-05 S8 -5.3396E-02 1.7636E-02 -1.2160E-02 2.0584E-03 4.4147E-04 -3.0511E-04 1.6697E-04 Face number A18 A20 A22 A24 A26 A28 A30 S3 -2.7087E-04 -1.3084E-04 -3.3474E-05 -2.0776E-05 -3.4946E-05 -2.8284E-05 0.0000E+00 S4 -6.1480E-04 -1.6711E-04 2.2223E-04 2.5136E-04 -1.9077E-04 1.6336E-05 1.6079E-05 S5 -4.6620E-04 -2.1073E-04 1.7100E-04 3.0285E-04 -1.9000E-04 -1.3177E-05 2.4992E-05 S6 -2.7543E-04 -3.5455E-04 -1.9022E-04 1.5549E-04 6.4208E-05 1.6031E-06 -1.3832E-05 S7 -2.0570E-05 -3.1726E-04 -2.1508E-04 1.5227E-04 6.6396E-05 2.9780E-06 -2.3352E-05 S8 1.6697E-04 -4.1951E-05 6.4861E-05 1.0939E-04 -4.5584E-05 -6.3380E-05 -1.6983E-05

[0132] Table 10

[0133] Figure 19 shows the astigmatism curve of the optical imaging system of Embodiment 5, which represents the meridional image plane curvature and the sagittal image plane curvature corresponding to different field angles. Figure 20 shows the distortion curve of the optical imaging system of Embodiment 5, which represents the distortion magnitude values corresponding to different field angles. Figure 21The relative illuminance curve of the optical imaging system of Embodiment 5 is shown, which represents the relative illuminance values corresponding to different field angles. According to Figures 19 to 21 it can be known that the optical imaging system of Embodiment 5 can achieve good imaging quality.

[0134] Embodiment 6

[0135] The following will refer to Figure 22 and Figures 23 to 25 describe the optical imaging system according to Embodiment 6 of the present application.

[0136] As Figure 22 shown, the optical imaging system includes, in order from the object side to the image side along the optical axis, an imaging lens group, a prism T, and an imaging surface. The imaging lens group includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0137] The first lens E1 has a negative optical power, its object surface S1 is convex, and its image surface S2 is concave; the second lens E2 has a positive optical power, its object surface S3 is convex, and its image surface S4 is concave; the third lens E3 has a negative optical power, its object surface S5 is convex, and its image surface S6 is concave; the fourth lens E4 has a positive optical power, its object surface S7 is convex, and its image surface S8 is concave.

[0138] The aperture stop STO is disposed between the fourth lens E4 and the prism T. A filter having an object surface S9 and an image surface S10 can be placed between the prism T and the imaging surface S11. Light from the object sequentially passes through the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, and is incident on the imaging surface S11 after multiple reflections (e.g., 3 times) inside the prism T.

[0139] 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).

[0140]

[0141] Table 11

[0142] In this embodiment, the object surface and the image surface of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces. Table 12 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 of the aspherical mirror surfaces S3 - S8 that can be used in Embodiment 6.

[0143]

[0144]

[0145] Table 12

[0146] Figure 23 Fig. 8 shows the astigmatism curve of the optical imaging system of Example 6, which represents the meridional field curvature and the sagittal field curvature corresponding to different field angles. Figure 24 Fig. 9 shows the distortion curve of the optical imaging system of Example 6, which represents the distortion values corresponding to different field angles. Figure 25 Fig. 10 shows the relative illumination curve of the optical imaging system of Example 6, which represents the relative illumination values corresponding to different field angles. According to Figures 23 to 25 it can be seen that the optical imaging system of Example 6 can achieve good imaging quality.

[0147] Table 13 shows the values of the parameters of TTL, ImgH, FOV, Fno, f, f1, f2, f3, f4, SL and TD of each of the Examples 1-6.

[0148] Example parameters 1 2 3 4 5 6 TTL (mm) 23.04 23.57 22.56 22.85 23.69 23.57 ImgH (mm) 3.98 3.98 3.98 3.98 3.98 3.98 FOV (°) 23.4 23.4 23.4 23.6 23.2 23.2 Fno 2.8 2.8 2.8 2.8 2.8 2.8 f (mm) 18.90 19.04 18.90 18.90 19.18 19.29 f1 (mm) -180.00 -181.00 -180.00 -180.00 -180.00 -180.00 f2 (mm) 6.39 7.86 12.39 7.98 9.66 10.30 f3 (mm) -7.57 -8.95 -10.79 -8.24 -10.58 -14.06 f4 (mm) 100.00 35.27 13.61 21.60 22.11 38.78 SL (mm) 5.87 7.66 6.64 6.14 7.78 7.65 TD (mm) 4.40 5.24 4.46 4.58 5.25 5.25

[0149] Table 13

[0150] Table 14 shows the values of the conditional expressions of each of the Examples 1-6.

[0151] Condition / Example 1 2 3 4 5 6 CT2 / CT1 2.57 2.36 1.75 1.45 1.36 1.43 f1 / f -9.52 -9.51 -9.52 -9.52 -9.39 -9.33 T12 / T23 2.14 2.17 2.95 2.56 3.21 2.81 R1 / R2 1.12 1.14 1.14 1.18 1.17 1.16 f1 / V1 -3.34 -3.36 -5.09 -3.63 -4.97 -3.34 f2 / f 0.34 0.41 0.66 0.42 0.50 0.53 f2 / R3 1.25 1.55 2.47 1.70 1.84 1.93 N1 / N2 1.11 1.11 1.17 1.15 1.17 1.11 CT1 / ET1 1.10 1.17 1.11 1.16 1.19 1.19 CT2 / (T23 + CT3) 4.89 4.20 4.12 4.16 2.21 2.29 R6 / R5 0.06 0.39 0.47 0.31 0.48 0.64 f4 / f3 -13.21 -3.94 -1.26 -2.62 -2.09 -2.76 f / f3 -2.50 -2.13 -1.75 -2.29 -1.81 -1.37 SAG32 / T34 4.88 1.04 15.78 6.73 1.01 0.96 f3 / R6 × N3 -2.86 -4.56 -5.12 -3.86 -4.99 -8.36 SL / TD 1.33 1.46 1.49 1.34 1.48 1.46

[0152] Table 14

[0153] The present application also provides an imaging device, the electronic photosensitive element of which may be a charge coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device may 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.

[0154] The above description is only a preferred embodiment of the present application and an explanation of the technical principles applied. Those skilled in the art should understand that the scope of the invention involved in the present 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 inventive concept. 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 the present application.

Claims

1. An optical imaging system sequentially includes an imaging lens group, a prism, and an imaging surface along the optical axis from the object side to the image side. The imaging lens group sequentially includes, along the optical axis from the object side to the image side: A first lens with negative optical power, having a convex object surface and a concave image surface; A second lens with positive optical power, having a convex object surface; A third lens with negative optical power, having a convex object surface and a concave image surface; and A fourth lens with positive optical power, having a convex object surface; Wherein, the number of lenses with optical power in the optical imaging system is four; The imaging lens group and the imaging surface are on the same side of the prism; Wherein, the maximum field of view FOV of the optical imaging system satisfies: 23.2° ≤ FOV ≤ 23.6°; The central thickness CT1 of the first lens on the optical axis and the central thickness CT2 of the second lens on the optical axis satisfy: 1.35 < CT2 / CT1 < 2.

6.

2. The optical imaging system according to claim 1, wherein: The first lens is a glass lens; The refractive index N1 of the first lens and the refractive index N2 of the second lens satisfy: 1.1 < N1 / N2 < 1.

2.

3. The optical imaging system according to claim 1, wherein: The total effective focal length f of the optical imaging system and the effective focal length f3 of the third lens satisfy: -2.5 ≤ f / f3 < -1.

35.

4. The optical imaging system according to claim 1, wherein: The curvature radius R1 of the object surface of the first lens and the curvature radius R2 of the image surface of the first lens satisfy: 1.1 < R1 / R2 < 1.2; The Abbe number V1 of the first lens and the effective focal length f1 of the first lens satisfy: -5.1 mm < f1 / V1 < -3.3 mm.

5. The optical imaging system according to claim 1, wherein: The total effective focal length f of the optical imaging system and the effective focal length f1 of the first lens satisfy: -9.55 < f1 / f < -9.

3.

6. The optical imaging system according to claim 1, wherein: The central thickness CT1 of the first lens on the optical axis and the edge thickness ET1 at the maximum effective radius of the first lens satisfy: 1.1 ≤ CT1 / ET1 ≤ 1.

2.

7. The optical imaging system according to claim 1, wherein: The effective focal length f2 of the second lens, the total effective focal length f of the optical imaging system, and the curvature radius R3 of the object surface of the second lens satisfy: 0.3 < f2 / f < 0.7 and 1.2 < f2 / R3 < 2.

5.

8. The optical imaging system according to claim 1, wherein: The curvature radius R5 of the object surface of the third lens and the curvature radius R6 of the object surface of the third lens satisfy: 0.05 < R6 / R5 < 0.

65.

9. The optical imaging system according to any one of claims 1 to 8, wherein: The effective focal length f4 of the fourth lens and the effective focal length f3 of the third lens satisfy: -13.25 < f4 / f3 < -1.

25.

10. The optical imaging system according to any one of claims 1 to 8, wherein: The central thickness CT2 of the second lens on the optical axis, the spacing distance T23 between the second lens and the third lens on the optical axis, and the central thickness CT3 of the third lens on the optical axis satisfy: 2.2 < CT2 / (T23 + CT3) < 4.9.

Images