Optical image capturing system

Abstract

The utility model provides an optical imaging system, which comprises a first lens to a seventh lens, a plurality of isolating rings and a lens barrel, the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f4 of the fourth lens meet the condition of 0 lt; r7 / f4lt; 0.8; the distance EP56 from the image side surface of the fifth isolating ring to the object side surface of the sixth isolating ring along the optical axis direction of the optical imaging system, the curvature radius R11 of the object side surface of the sixth lens and the effective focal length f6 of the sixth lens meet the following conditions: 1.5 mmlt; eP56 / (R11 / f6) lt; the thickness is 2.5 mm; the effective focal length f6 of the sixth lens, the inner diameter d6s of the object side surface of the sixth isolating ring, the effective focal length f7 of the seventh lens and the inner diameter d6m of the image side surface of the sixth isolating ring meet the following conditions: 1.0 lt; f < 6 > / d < 6 > s-f < 7 > / d < 6 > mlt; 2.0. The utility model solves the problem of serious stray light at the rear end of the optical imaging system in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of optical imaging devices, and more particularly to an optical imaging system. Background Art

[0002] With the application and development of optical imaging systems in mobile phones, tablet computers, and intelligent imaging fields, the requirements for optical imaging systems have become increasingly high due to the changes in usage scenarios. To meet the changing needs of various usage scenarios, optical imaging systems should have a large field of view and unique imaging effects. As a result, the number of lenses used in optical imaging systems is increasing, and the lens forms are also more diverse. Especially for a seven-lens optical imaging system, there is an easy-to-occur large step difference between two adjacent lenses at the rear end of the system, leading to a more complex stray light path reflected and refracted on the lens surface. The generation of a large amount of stray light seriously affects the imaging effect. Therefore, how to control the optical parameters of the rear-end lenses of the optical imaging system and the inner diameter size of the spacer rings, reduce stray light while ensuring stable assembly, and improve the imaging effect is a very important issue. Summary of the Utility Model

[0003] The main purpose of the utility model is to provide an optical imaging system to solve the problem of serious stray light at the rear end of the optical imaging system in the prior art.

[0004] To achieve the above object, according to one aspect of the utility model, there is provided an optical imaging system, including: a lens group, which sequentially includes a first lens to a seventh lens from the object side to the image side of the optical imaging system. The optical power of the first lens is positive, the optical power of the second lens is negative, the optical power of the third lens is positive, the optical power of the fourth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative; a plurality of spacer rings, the plurality of spacer rings at least include a fourth spacer ring located between the fourth lens and the fifth lens and at least partially in contact with the image side surface of the fourth lens, a fifth spacer ring located between the fifth lens and the sixth lens and at least partially in contact with the image side surface of the fifth lens, and a sixth spacer ring located between the sixth lens and the seventh lens and at least partially in contact with the image side surface of the sixth lens; a lens barrel, the lens barrel is used to accommodate the lens group and the plurality of spacer rings; wherein, the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f4 of the fourth lens satisfy: 0 < R7 / f4 < 0.8; the distance EP56 along the optical axis direction of the optical imaging system from the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring, the curvature radius R11 of the object side surface of the sixth lens, and the effective focal length f6 of the sixth lens satisfy: 1.5mm < EP56 / (R11 / f6) < 2.5mm; the effective focal length f6 of the sixth lens, the inner diameter d6s of the object side surface of the sixth spacer ring, the effective focal length f7 of the seventh lens, and the inner diameter d6m of the image side surface of the sixth spacer ring satisfy: 1.0 < f6 / d6s - f7 / d6m < 2.0.

[0005] According to another aspect of the present utility model, an optical imaging system is provided, including: a lens group, which sequentially includes a first lens to a seventh lens from the object side to the image side of the optical imaging system. The optical power of the first lens is positive, the optical power of the second lens is negative, the optical power of the third lens is positive, the optical power of the fourth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative; a plurality of spacer rings, the plurality of spacer rings at least include a fourth spacer ring located between the fourth lens and the fifth lens and at least partially contacting the image side surface of the fourth lens, a fifth spacer ring located between the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens, and a sixth spacer ring located between the sixth lens and the seventh lens and at least partially contacting the image side surface of the sixth lens; a lens barrel for accommodating the lens group and the plurality of spacer rings; wherein, the distance EP45 along the optical axis direction from the image side surface of the fourth spacer ring to the object side surface of the fifth spacer ring, the distance EP56 along the optical axis direction from the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring, the effective focal length f6 of the sixth lens, and the effective focal length f4 of the fourth lens satisfy: -20.0mm < (EP45 + EP56) / (f6 / f4) < -10.0mm; the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f4 of the fourth lens satisfy: 0 < R7 / f4 < 0.8; the curvature radius R12 of the image side surface of the sixth lens and the effective focal length f6 of the sixth lens satisfy: 0 < R12 / f6 < 20.0, and the inner diameter d4m of the image side surface of the fourth spacer ring, the curvature radius R8 of the image side surface of the fourth lens, and the curvature radius R7 of the object side surface of the fourth lens satisfy: 0.1mm < d4m / (R8 / R7) < 5.0mm. The present application provides a seven-piece optical imaging system. The optical powers of the first lens, the third lens, and the sixth lens are positive, and the optical powers of the second lens, the fourth lens, and the seventh lens are negative. By reasonably controlling the positive and negative distribution of the optical powers of the respective lenses of the optical imaging system, and controlling -20.0mm < (EP45 + EP56) / (f6 / f4) < -10.0mm, 0 < R7 / f4 < 0.8, 0 < R12 / f6 < 20.0, the low-order aberrations of the optical imaging system are effectively balanced, the sensitivity to the tolerances of the fourth lens and the sixth lens is reduced, the chromatic aberration is corrected, the field curvature contributions of the fourth lens and the sixth lens are within a reasonable range, and the optical sensitivity between the object side surface of the fourth lens and the image side surface of the sixth lens is reduced. However, this design causes a large step difference at the positions of the fourth to sixth lenses of the optical imaging system, which is likely to cause stray light problems. Affected by the thickness of the spacer rings, the more complex the structure of the spacer rings, the more complex the stray light state. The present application helps to improve the spherical aberration and astigmatism of the system by controlling the inner diameter size of the fourth spacer ring and the curvature radii of the object side surface and the image side surface of the fourth lens, and while ensuring the stable assembly of the fourth spacer ring group, improves the reflected stray light, thereby enhancing the imaging quality of the system.

[0006] According to another aspect of the present utility model, an optical imaging system is provided, comprising: a lens group, which sequentially includes a first lens to a seventh lens from the object side to the image side of the optical imaging system. The optical power of the first lens is positive, the optical power of the second lens is negative, the optical power of the third lens is positive, the optical power of the fourth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative; a plurality of spacer rings, the plurality of spacer rings at least include a fourth spacer ring located between the fourth lens and the fifth lens and at least partially contacting the image side surface of the fourth lens, a fifth spacer ring located between the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens, and a sixth spacer ring located between the sixth lens and the seventh lens and at least partially contacting the image side surface of the sixth lens; a lens barrel for accommodating the lens group and the plurality of spacer rings; wherein, the distance EP45 along the optical axis direction from the image side surface of the fourth spacer ring to the object side surface of the fifth spacer ring, the distance EP56 along the optical axis direction from the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring, the effective focal length f6 of the sixth lens, and the effective focal length f4 of the fourth lens satisfy: -20.0mm < (EP45 + EP56) / (f6 / f4) < -10.0mm; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f4 of the fourth lens satisfy: 0 < R7 / f4 < 0.8; the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f6 of the sixth lens satisfy: 0 < R12 / f6 < 20.0; the inner diameter d5s of the object side surface of the fifth spacer ring, the radius of curvature R10 of the image side surface of the fifth lens, and the radius of curvature R9 of the object side surface of the fifth lens satisfy: -10.0mm < d5s / (R10 / R9) < 10.0mm. The present application provides a seven-piece optical imaging system. The optical powers of the first lens, the third lens, and the sixth lens are positive, and the optical powers of the second lens, the fourth lens, and the seventh lens are negative. By reasonably controlling the positive and negative distribution of the optical powers of the respective lenses of the optical imaging system, and controlling -20.0mm < (EP45 + EP56) / (f6 / f4) < -10.0mm, 0 < R7 / f4 < 0.8, 0 < R12 / f6 < 20.0, the low-order aberrations of the optical imaging system are effectively balanced, the sensitivity of the tolerances of the fourth and sixth lenses is reduced, the chromatic aberration is corrected, the field curvature contributions of the fourth lens and the sixth lens are within a reasonable range, and the optical sensitivity between the object side surface of the fourth lens and the image side surface of the sixth lens is reduced. However, this design causes a large step difference at the positions of the fourth to sixth lenses of the optical imaging system, which is likely to cause stray light problems. Affected by the thickness of the spacer rings, the more complex the structure of the spacer rings, the more complex the stray light state will be.The present application controls the curvature radii of the object side and the image side of the fifth lens and the inner diameter of the fifth isolation ring, while ensuring the large step difference between the fifth lens and the sixth lens, further intercepts stray light, improves the spherical aberration and astigmatism of the system, effectively controls the field curvature of the system, improves the imaging quality, and makes the transition between the optical part and the structural part of the fifth lens smoother, which is conducive to improving the processability of the fifth lens.

[0007] According to another aspect of the present utility model, an optical imaging system is provided, including: a lens group, which sequentially includes a first lens to a seventh lens from the object side to the image side of the optical imaging system. The optical power of the first lens is positive, the optical power of the second lens is negative, the optical power of the third lens is positive, the optical power of the fourth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative; a plurality of spacer rings, which at least include a fourth spacer ring located between the fourth lens and the fifth lens and at least partially contacting the image side surface of the fourth lens, a fifth spacer ring located between the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens, and a sixth spacer ring located between the sixth lens and the seventh lens and at least partially contacting the image side surface of the sixth lens; a lens barrel for accommodating the lens group and the plurality of spacer rings; wherein, the distance EP45 along the optical axis direction from the image side surface of the fourth spacer ring to the object side surface of the fifth spacer ring, the dispersion coefficient V4 of the fourth lens, the dispersion coefficient V5 of the fifth lens, and the effective focal length f4 of the fourth lens satisfy: -1.5 < EP45 * (V4 + V5) / f4 < -0.1. The curvature radius R7 of the object side surface of the fourth lens and the effective focal length f4 of the fourth lens satisfy: 0 < R7 / f4 < 0.8; the curvature radius R12 of the image side surface of the sixth lens and the effective focal length f6 of the sixth lens satisfy: 0 < R12 / f6 < 20.0. The inner diameter d4m of the image side surface of the fourth spacer ring, the curvature radius R8 of the image side surface of the fourth lens, and the curvature radius R7 of the object side surface of the fourth lens satisfy: 0.1 mm < d4m / (R8 / R7) < 5.0 mm. The present application provides a seven-piece optical imaging system. The optical powers of the first lens, the third lens, and the sixth lens are positive, and the optical powers of the second lens, the fourth lens, and the seventh lens are negative. By reasonably controlling the positive and negative distribution of the optical powers of the respective lenses of the optical imaging system, and controlling -1.5 < EP45 * (V4 + V5) / f4 < -0.1, 0 < R7 / f4 < 0.8, 0 < R12 / f6 < 20.0, the low-order aberrations of the optical imaging system are effectively balanced, the sensitivity to the tolerances of the fourth and sixth lenses is reduced, chromatic aberration is corrected, the field curvature contributions of the fourth lens and the sixth lens are within a reasonable range, the optical sensitivity between the object side surface of the fourth lens and the image side surface of the sixth lens is reduced, and it is also helpful to control the edge thickness of the fifth lens and reduce the difficulty of forming the fifth lens. However, this design results in a large step difference at the positions of the fourth to sixth lenses of the optical imaging system, which is likely to cause stray light problems. Affected by the thickness of the spacer rings, the more complex the structure of the spacer rings, the more complex the stray light state. The present application helps to improve the spherical aberration and astigmatism of the system by controlling the inner diameter size of the fourth spacer ring and the curvature radii of the object side surface and the image side surface of the fourth lens, and improves the reflected stray light while ensuring the stable assembly of the fourth spacer ring group, thereby improving the imaging quality of the system.

[0008] Furthermore, the inner diameter d5s of the image side of the fifth spacer ring, the radius of curvature R10 of the image side of the fifth lens, and the radius of curvature R9 of the object side of the fifth lens satisfy: -10.0 mm < d5s / (R10 / R9) < 10.0 mm.

[0009] Furthermore, the inner diameter d5m of the image side of the fifth spacer ring and the radius of curvature R12 of the image side of the sixth lens satisfy: 0 < d5m / R12 < 1.0.

[0010] Furthermore, the distance EP45 along the optical axis from the image side of the fourth spacer ring to the object side of the fifth spacer ring, the dispersion coefficient V4 of the fourth lens, the dispersion coefficient V5 of the fifth lens, and the effective focal length f4 of the fourth lens satisfy: -1.5 < EP45*(V4 + V5) / f4 < -0.1.

[0011] Furthermore, the plurality of spacer rings further includes a third spacer ring located between the third lens and the fourth lens and at least partially in contact with the image side of the third lens. The refractive index N4 of the fourth lens, the distance EP34 along the optical axis from the image side of the third spacer ring to the object side of the fourth spacer ring, the radius of curvature R8 of the image side of the fourth lens, and the effective focal length f of the optical imaging system satisfy: -1.0 mm < N4*EP34 / (R8 / f) < 0 mm.

[0012] Furthermore, the effective focal length f6 of the sixth lens and the height L of the lens barrel satisfy: 0.2 < f6 / L < 2.0. The air gap T56 between the fifth lens and the sixth lens on the optical axis, the maximum thickness CP5 of the fifth spacer ring along the optical axis, and the distance EP56 along the optical axis from the image side of the fifth spacer ring to the object side of the sixth spacer ring satisfy: 0 < T56 / (CP5 + EP56) < 1.0.

[0013] Furthermore, the plurality of spacer rings further includes a first spacer ring located between the first lens and the second lens and at least partially in contact with the image side of the first lens, a second spacer ring located between the second lens and the third lens and at least partially in contact with the image side of the second lens, and a third spacer ring located between the third lens and the fourth lens and at least partially in contact with the image side of the third lens. The inner diameter of the object side of the second spacer ring is the smallest among the inner diameters of the object sides of the first to sixth spacer rings. The inner diameter d2s of the object side of the second spacer ring, the inner diameter d1s of the object side of the first spacer ring, the effective focal length f1 of the first lens, the inner diameter d3s of the object side of the third spacer ring, the inner diameter d2s of the object side of the second spacer ring, and the effective focal length f3 of the third lens satisfy: 0 < [(d2s - d1s)*f1] / [(d3s - d2s)*f3] < 1.0.

[0014] Furthermore, the plurality of isolating rings further include a first isolating ring located between the first lens and the second lens and at least partially in contact with the image side surface of the first lens, and a distance EP01 from the object side end surface of the lens barrel to the object side surface of the first isolating ring along the optical axis and a center thickness CT1 of the first lens on the optical axis satisfy the following conditions: 1.0 <EP01 / CT1<1.5。

[0015] Further, the combined focal length f56 of the fifth lens and the sixth lens, the air gap T56 between the fifth lens and the sixth lens on the optical axis, the maximum thickness CP6 of the sixth isolation ring along the optical axis, and the height L of the lens barrel satisfy: 0.5<(f56-T56-CP6) / L<1.5.

[0016] Furthermore, the plurality of isolating rings further include a first isolating ring located between the first lens and the second lens and at least partially in contact with the image side surface of the first lens, and a distance EP01 from the object side end surface of the lens barrel to the object side surface of the first isolating ring along the optical axis, and an axial distance SAGH11 from the intersection of the object side surface of the first lens and the optical axis to the vertex of the effective radius of the object side surface of the first lens satisfy the following conditions: 1.0 <EP01 / |SAGH11|<1.5。

[0017] Furthermore, the outer diameter D6s of the object side surface of the sixth isolation ring, the outer diameter D5m of the image side surface of the fifth isolation ring, the maximum effective radius DT61 of the object side surface of the sixth lens, and the maximum effective radius DT62 of the image side surface of the sixth lens satisfy: 0<(D6s-D5m) / (DT61+DT62)<0.8.

[0018] Furthermore, the plurality of isolation rings further include a fifth auxiliary element located between the fifth isolation ring and the sixth lens and at least partially in contact with the image side surface of the fifth isolation ring, and the inner diameter d5bs of the object side surface of the fifth auxiliary element and the vertical distance Yc61 from the inflection point on the object side surface of the sixth lens to the optical axis satisfy the following relationship: 2.5 <d5bs / Yc61<4.0。

[0019] Furthermore, the multiple isolation rings also include a fifth auxiliary element located between the fifth isolation ring and the sixth lens and at least partially in contact with the image side surface of the fifth isolation ring, and the inner diameter d5bs of the object side surface of the fifth auxiliary element, the vertical distance Yc61 from the inflection point on the object side surface of the sixth lens to the optical axis, and the effective focal length f6 of the sixth lens satisfy: 0.1<(d5s-Yc61) / f6<1.5.

[0020] Further, the plurality of spacer rings further includes a second spacer ring located between the second lens and the third lens and at least partially contacting the image side surface of the second lens. The following relationship is satisfied among the outer diameter D2s of the object side surface of the second spacer ring, the maximum effective radius DT22 of the image side surface of the second lens, and the maximum effective radius DT31 of the object side surface of the third lens: 0.6 < (D2s - DT22 * 2) / (D2s - DT31 * 2) < 1.2.

[0021] Further, the following relationship is satisfied among the effective focal length f of the optical imaging system, the field of view angle FOV of the optical imaging system, the minimum inner diameter ds of the lens barrel, and the inner diameter d2s of the object side surface of the second spacer ring: 3.0 < f * tan(FOV / 2) / (ds - d2s) < 4.5.

[0022] Further, the plurality of spacer rings further includes a sixth auxiliary element located between the sixth spacer ring and the seventh lens and at least partially contacting the image side surface of the sixth spacer ring.

[0023] Further, the following relationship is satisfied among the distance EP45 along the optical axis direction from the image side surface of the fourth spacer ring to the object side surface of the fifth spacer ring, the distance EP56 along the optical axis direction from the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring, the effective focal length f6 of the sixth lens, and the effective focal length f4 of the fourth lens: -20.0 mm < (EP45 + EP56) / (f6 / f4) < -10.0 mm.

[0024] Further, the following relationship is satisfied between the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f6 of the sixth lens: 0 < R12 / f6 < 20.0. The following relationship is satisfied among the inner diameter d4m of the image side surface of the fourth spacer ring, the radius of curvature R8 of the image side surface of the fourth lens, and the radius of curvature R7 of the object side surface of the fourth lens: 0.1 mm < d4m / (R8 / R7) < 5.0 mm.

[0025] Applying the technical solution of the present utility model, the optical imaging system includes a lens group, a plurality of spacer rings, and a lens barrel. Along the object side to the image side of the optical imaging system, the optical imaging system sequentially includes a first lens to a seventh lens. The optical power of the first lens is positive, the optical power of the second lens is negative, the optical power of the third lens is positive, the optical power of the fourth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative; the plurality of spacer rings at least include a fourth spacer ring located between the fourth lens and the fifth lens and at least partially contacting the image side surface of the fourth lens, a fifth spacer ring located between the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens, and a sixth spacer ring located between the sixth lens and the seventh lens and at least partially contacting the image side surface of the sixth lens; the lens barrel is used to accommodate the lens group and the plurality of spacer rings; wherein, the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f4 of the fourth lens satisfy: 0 < R7 / f4 < 0.8; the distance EP56 along the optical axis direction of the optical imaging system from the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring, the curvature radius R11 of the object side surface of the sixth lens, and the effective focal length f6 of the sixth lens satisfy: 1.5 mm < EP56 / (R11 / f6) < 2.5 mm; the effective focal length f6 of the sixth lens, the inner diameter d6s of the object side surface of the sixth spacer ring, the effective focal length f7 of the seventh lens, and the inner diameter d6m of the image side surface of the sixth spacer ring satisfy: 1.0 < f6 / d6s - f7 / d6m < 2.0.

[0026] This application provides a seven-piece optical imaging system. The optical powers of the first lens, the third lens, and the sixth lens are positive, and the optical powers of the second lens, the fourth lens, and the seventh lens are negative. By reasonably controlling the positive and negative distribution of the optical powers of the respective lenses of the optical imaging system, and controlling 0 < R7 / f4 < 0.8 and 1.5 mm < EP56 / (R11 / f6) < 2.5 mm, the low-order aberrations of the optical imaging system can be effectively balanced and controlled, the sensitivity of the position tolerance of the sixth lens can be reduced, and at the same time, it is helpful to improve the assembly stability of the lenses near the positions of the fifth and sixth lenses. However, this design results in a large step difference at the positions of the fifth and sixth lenses of the optical imaging system, which is likely to cause stray light problems. Affected by the thickness of the spacer rings, the more complex the structure of the spacer rings, the more complex the stray light state. By controlling the parameter relationship between the effective focal lengths of the sixth lens and the seventh lens and the inner diameter size of the sixth spacer ring, it is beneficial to ensure the stable assembly of the sixth spacer ring while improving the reflected stray light, thereby helping to improve the imaging quality of the system. Description of the Drawings

[0027] The schematic drawings forming a part of this application are used to provide a further understanding of the present utility model. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0028] Figure 1 A partial parameter schematic diagram of an optical imaging system of an optional embodiment of the utility model is shown;

[0029] Figure 2 A schematic diagram of the structure of an optical imaging system according to a first embodiment of the present utility model is shown;

[0030] Figures 3 to 6 The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the first embodiment of the utility model are respectively shown;

[0031] Figure 7 A schematic diagram showing the structure of an optical imaging system according to a second embodiment of the present utility model is shown;

[0032] Figure 8 A schematic diagram showing the structure of an optical imaging system according to a third embodiment of the present invention is shown;

[0033] Fig. 9 A schematic diagram showing the structure of an optical imaging system according to a fourth embodiment of the present utility model is shown;

[0034] Figures 10 to 13 The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the fourth embodiment of the utility model are respectively shown;

[0035] Fig.14 The structure diagram of the optical imaging system of the fifth embodiment of the present utility model is shown;

[0036] Fig.15 A schematic diagram showing the structure of an optical imaging system according to a sixth embodiment of the present utility model is shown;

[0037] Fig.16 The structure diagram of the optical imaging system of the seventh embodiment of the present utility model is shown;

[0038] Figures 17 to 20 The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the seventh embodiment of the utility model are respectively shown;

[0039] Fig.21 The structure diagram of the optical imaging system of the eighth embodiment of the present utility model is shown;

[0040] Fig. 22 A schematic diagram showing the structure of an optical imaging system according to a ninth embodiment of the present utility model is shown;

[0041] Fig.23 The stray light energy spot diagram of the optical imaging system of an optional embodiment of the utility model under the conditions of EP56 / (R11 / f6)=2.39, R7 / f4=1.18, f6 / d6s-f7 / d6m=0.64 is shown;

[0042] Fig.24 The stray light energy spot diagram of the optical imaging system under the conditions of EP56 / (R11 / f6)=0.85, R7 / f4=-5.38, f6 / d6s-f7 / d6m=0.82 is shown;

[0043] Fig.25 The stray light energy spot diagram of the optical imaging system under the conditions of EP56 / (R11 / f6)=1.88, R7 / f4=0.81, f6 / d6s-f7 / d6m=6.02 is shown.

[0044] The above drawings include the following reference numerals:

[0045] E1, first lens; S1, object-side surface of the first lens; S2, image-side surface of the first lens; P1, first isolating ring; E2, second lens; S3, object-side surface of the second lens; S4, image-side surface of the second lens; P2, second isolating ring; E3, third lens; S5, object-side surface of the third lens; S6, image-side surface of the third lens; P3, third isolating ring; E4, fourth lens; S7, object-side surface of the fourth lens; S8, image-side surface of the fourth lens; P4, fourth isolating ring; E5, The fifth lens; S9, the object side surface of the fifth lens; S10, the image side surface of the fifth lens; P5, the fifth isolation ring; P5b, the fifth auxiliary element; P5c, the fifth auxiliary ring; E6, the sixth lens; S11, the object side surface of the sixth lens; S12, the image side surface of the sixth lens; P6, the sixth isolation ring; P6b, the sixth auxiliary isolation ring; P6c, the sixth auxiliary ring; E7, the seventh lens; S13, the object side surface of the seventh lens; S14, the image side surface of the seventh lens; P7, the seventh isolation ring. DETAILED DESCRIPTION

[0046] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0048] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0049] 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.

[0050] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0051] 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 close to the object side is called the object side surface of the lens, and the surface of each lens close to the image side is called the image side surface of the lens. The judgment of the surface shape in the paraxial region can be based on the judgment method of the general knowledge in this field, and the positive and negative R value (R refers to the radius of curvature of the paraxial region, usually refers to the R value on the lens database (lens data) in the optical software) is used to judge the concave and convex. For the object side, when the R value is positive, it is judged as a convex surface, and when the R value is negative, it is judged as a concave surface; for the image side, when the R value is positive, it is judged as a concave surface, and when the R value is negative, it is judged as a convex surface.

[0052] In order to solve the problem of serious stray light at the rear end of an optical imaging system in the prior art, the utility model provides an optical imaging system.

[0053] First embodiment

[0054] like Figures 1 to 23As shown in the figure, the optical imaging system includes a lens group, a plurality of spacer rings, and a lens barrel. Along the object side to the image side of the optical imaging system, the optical imaging system sequentially includes a first lens to a seventh lens. The optical power of the first lens is positive, the optical power of the second lens is negative, the optical power of the third lens is positive, the optical power of the fourth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative. The plurality of spacer rings at least include a fourth spacer ring located between the fourth lens and the fifth lens and at least partially contacting the image side surface of the fourth lens, a fifth spacer ring located between the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens, and a sixth spacer ring located between the sixth lens and the seventh lens and at least partially contacting the image side surface of the sixth lens. The lens barrel is used to accommodate the lens group and the plurality of spacer rings. Among them, the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f4 of the fourth lens satisfy: 0 < R7 / f4 < 0.8; the distance EP56 along the optical axis direction of the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring, the curvature radius R11 of the object side surface of the sixth lens, and the effective focal length f6 of the sixth lens satisfy: 1.5 mm < EP56 / (R11 / f6) < 2.5 mm; the effective focal length f6 of the sixth lens, the inner diameter d6s of the object side surface of the sixth spacer ring, the effective focal length f7 of the seventh lens, and the inner diameter d6m of the image side surface of the sixth spacer ring satisfy: 1.0 < f6 / d6s - f7 / d6m < 2.0.

[0055] This application provides a seven-piece optical imaging system. The optical powers of the first lens, the third lens, and the sixth lens are positive, and the optical powers of the second lens, the fourth lens, and the seventh lens are negative. By reasonably controlling the positive and negative distribution of the optical powers of the respective lenses of the optical imaging system, and controlling 0 < R7 / f4 < 0.8 and 1.5 mm < EP56 / (R11 / f6) < 2.5 mm, the low-order aberrations of the optical imaging system can be effectively balanced and controlled, the sensitivity of the position tolerance of the sixth lens can be reduced, and at the same time, it can help improve the assembly stability of the lenses near the positions of the fifth and sixth lenses. However, this design results in a large step difference at the positions of the fifth and sixth lenses of the optical imaging system, which is likely to cause stray light problems. Affected by the thickness of the spacer rings, the more complex the structure of the spacer rings, the more complex the stray light state. By controlling the parameter relationship between the effective focal lengths of the sixth lens and the seventh lens and the inner diameter size of the sixth spacer ring, this application is beneficial to ensuring the stable assembly of the sixth spacer ring while improving the reflected stray light, thereby helping to improve the imaging quality of the system.

[0056] Preferably, 0.05 < R7 / f4 < 0.70.

[0057] Preferably, 1.6 mm < EP56 / (R11 / f6) < 2.4 mm.

[0058] Preferably, 1.05 < f6 / d6s - f7 / d6m < 1.95.

[0059] Fig.24 For the optical imaging system shown, when EP56 / (R11 / f6) < 1.5, R7 / f4 < 0, and f6 / d6s - f7 / d6m < 1.0 (exemplarily, for example: EP56 / (R11 / f6) = 0.85, R7 / f4 = -5.38, f6 / d6s - f7 / d6m = 0.82), the maximum energy intensity of stray light is approximately 0.000006275 lm / mm 2 , and the total energy intensity is approximately 0.000003128 lm. Fig.25 For the optical imaging system of, when 1.5 mm < EP56 / (R11 / f6) < 2.5 mm, R7 / f4 > 0.8, and 1 < f6 / d6s - f7 / d6m > 2.0 (exemplarily, for example: EP56 / (R11 / f6) = 1.88, R7 / f4 = 0.81, f6 / d6s - f7 / d6m = 6.02), the maximum energy intensity of stray light is approximately 0.000003875 lm / mm 2 , and the total energy intensity is approximately 0.000001528 lm.

[0060] For the optical imaging system of an alternative embodiment of the present application, when 1.5 < EP56 / (R11 / f6) < 2.5, 0 < R7 / f4 < 0.8, and 1.0 < f6 / d6s - f7 / d6m < 2.0 (exemplarily, for example: EP56 / (R11 / f6) = 2.39, R7 / f4 = 1.18, f6 / d6s - f7 / d6m = 0.64), the spot pattern of the stray light energy is as shown in Fig.23 , and it can be seen from the figure that the maximum energy intensity is approximately 0.000000863 lm / mm 2 , and the total energy intensity is approximately 0.00000736 lm. Compared with Fig.24 and Fig.25 the prior art shown, the present application can achieve a better stray light improvement effect.

[0061] In this embodiment, the inner diameter d5s of the object side surface of the fifth spacer ring, the curvature radius R10 of the image side surface of the fifth lens, and the curvature radius R9 of the object side surface of the fifth lens satisfy: -10.0 mm < d5s / (R10 / R9) < 10.0 mm. By restricting d5s / (R10 / R9) within a reasonable range and controlling the curvature radii of the object side surface and the image side surface of the fifth lens, it helps to improve the spherical aberration and astigmatism of the system. At the same time, by controlling the bending direction of the fifth lens, the field curvature of the system can be effectively controlled, and the image quality of the system can be improved. Combining the control of the inner diameter of the object side surface of the fifth spacer ring, the transition between the optical part and the structural part of the fifth lens becomes smoother, which is beneficial to improving the processability of the fifth lens, further intercepting stray light, and enhancing the imaging quality. Preferably, -8.5 mm < d5s / (R10 / R9) < 9.0 mm.

[0062] In this embodiment, the inner diameter d5m of the image side surface of the fifth spacer ring and the curvature radius R12 of the image side surface of the sixth lens satisfy: 0 < d5m / R12 < 1.0. By restricting d5m / R12 within a reasonable range, the bending range of light can be better controlled, so as to effectively control the field curvature of the system and improve the imaging quality of the system. Preferably, 0.1 < d5m / R12 < 0.8.

[0063] In this embodiment, the distance EP45 along the optical axis direction from the image side surface of the fourth spacer ring to the object side surface of the fifth spacer ring, the dispersion coefficient V4 of the fourth lens, the dispersion coefficient V5 of the fifth lens, and the effective focal length f4 of the fourth lens satisfy: -1.5 < EP45 * (V4 + V5) / f4 < -0.1. By restricting EP45 * (V4 + V5) / f4 within a reasonable range, it helps to control the edge thickness of the fifth lens, reduce the difficulty of forming the fifth lens, and at the same time, the influence of the fourth and fifth lenses on the chromatic aberration of the system can be better adjusted, and the imaging quality of the system can be improved. Preferably, -1.45 < EP45 * (V4 + V5) / f4 < -0.15.

[0064] In this embodiment, the plurality of spacer rings further includes a third spacer ring located between the third lens and the fourth lens and at least partially in contact with the image side surface of the third lens. The refractive index N4 of the fourth lens, the distance EP34 along the optical axis from the image side surface of the third spacer ring to the object side surface of the fourth spacer ring, the radius of curvature R8 of the image side surface of the fourth lens, and the effective focal length f of the optical imaging system satisfy: -1.0 mm < N4 * EP34 / (R8 / f) < 0 mm. By restricting N4 * EP34 / (R8 / f) within a reasonable range, since the fourth lens is a convex lens, it helps more light enter the subsequent lenses; it also helps control the edge thickness of the fourth lens and reduces the difficulty of forming the fourth lens; it can control the curvature of the image side surface of the fourth lens, effectively reduce axial chromatic aberration, and ensure good imaging quality. Reasonably controlling the values of the above parameters can better ensure the imaging quality of the fourth lens and reduce the internal stray light of the fourth lens. Preferably, -0.8 mm < N4 * EP34 / (R8 / f) < 0 mm.

[0065] In this embodiment, the effective focal length f6 of the sixth lens and the height L of the lens barrel satisfy: 0.2 < f6 / L < 2.0, and the air gap T56 between the fifth lens and the sixth lens on the optical axis, the maximum thickness CP5 of the fifth spacer ring along the optical axis, and the distance EP56 along the optical axis from the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring satisfy: 0 < T56 / (CP5 + EP56) < 1.0. By restricting f6 / L and T56 / (CP5 + EP56) within reasonable ranges, controlling the focal length range of the sixth lens can reasonably control the contribution range of the optical power and the contribution rate of its negative spherical aberration, enabling it to reasonably balance the positive optical power of the sixth lens while facilitating the correction of axial spherical aberration and off-axis coma; it can also better control the step difference between the fifth lens and the sixth lens and ensure system stability. Preferably, 0.3 < f6 / L < 1.5, 0 < T56 / (CP5 + EP56) < 0.95.

[0066] In this embodiment, the plurality of spacer rings further includes a first spacer ring located between the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer ring located between the second lens and the third lens and at least partially contacting the image side surface of the second lens, and a third spacer ring located between the third lens and the fourth lens and at least partially contacting the image side surface of the third lens. The inner diameter of the object side surface of the second spacer ring is the smallest among the inner diameters of the object side surfaces of the first spacer ring to the sixth spacer ring. The inner diameter d2s of the object side surface of the second spacer ring, the inner diameter d1s of the object side surface of the first spacer ring, the effective focal length f1 of the first lens, the inner diameter d3s of the object side surface of the third spacer ring, the inner diameter d2s of the object side surface of the second spacer ring, and the effective focal length f3 of the third lens satisfy: 0 < [(d2s - d1s) * f1] / [(d3s - d2s) * f3] < 1.0. By limiting [(d2s - d1s) * f1] / [(d3s - d2s) * f3] within a reasonable range, it helps to ensure that the inner diameter of the object side surface of the first, second, and third spacer rings is close to the optical outer diameter of the image side surface of the previous adjacent lens. At the same time, the inner diameter of the object side surface of the first, second, and third spacer rings is equal to the inner diameter of the image side surface of the first, second, and third spacer rings, so that the inner diameter of the image side surface of the spacer ring should be close to the optical outer diameter of the object side surface of the next adjacent lens, improving the light blocking effect at this position; and it also helps to reduce the sensitivity of the first lens, the second lens, and the third lens. Preferably, 0.25 < [(d2s - d1s) * f1] / [(d3s - d2s) * f3] < 0.55.

[0067] In this embodiment, the plurality of spacer rings further includes a first spacer ring located between the first lens and the second lens and at least partially contacting the image side surface of the first lens. The distance EP01 from the object side end surface of the lens barrel to the object side surface of the first spacer ring along the optical axis direction and the central thickness CT1 of the first lens on the optical axis satisfy: 1.0 < EP01 / CT1 < 1.5. By limiting EP01 / CT1 within a reasonable range, when the thickness of one end of the lens barrel close to the image side is fixed, it helps to control the edge thickness of the first lens and reduce the processing and assembly difficulty. Preferably, 1.1 < EP01 / CT1 < 1.4.

[0068] In this embodiment, the combined focal length f56 of the fifth lens and the sixth lens, the air gap T56 between the fifth lens and the sixth lens on the optical axis, the maximum thickness CP6 of the sixth spacer ring in the optical axis direction, and the height L of the lens barrel satisfy: 0.5 < (f56 - T56 - CP6) / L < 1.5. By restricting (f56 - T56 - CP6) / L within a reasonable range, it is possible to reasonably control the contribution range of the combined focal length of the fifth lens and the sixth lens and the contribution rate of the negative spherical aberration of the fifth lens and the sixth lens, so as to reasonably balance the positive optical power of the combined focal length of the fifth lens and the sixth lens, and at the same time facilitate the correction of the on-axis spherical aberration and off-axis coma of the fifth lens and the sixth lens. Preferably, 0.6 < (f56 - T56 - CP6) / L < 1.4.

[0069] In this embodiment, the plurality of spacer rings further includes a first spacer ring located between the first lens and the second lens and at least partially in contact with the image side surface of the first lens. The distance EP01 along the optical axis from the object-side end face of the lens barrel to the object-side surface of the first spacer ring and the axial distance SAGH11 between the intersection of the object-side surface of the first lens and the optical axis and the vertex of the effective radius of the object-side surface of the first lens satisfy: 1.0 < EP01 / |SAGH11| < 1.5. By restricting EP01 / |SAGH11| within a reasonable range, it is beneficial to adjust the chief ray angle of the system, can effectively improve the relative brightness of the system, and enable the system to form a clear image. Preferably, 1.1 < EP01 / |SAGH11| < 1.4.

[0070] In this embodiment, the outer diameter D6s of the object-side surface of the sixth spacer ring, the outer diameter D5m of the image-side surface of the fifth spacer ring, the maximum effective radius DT61 of the object-side surface of the sixth lens, and the maximum effective radius DT62 of the image-side surface of the sixth lens satisfy: 0 < (D6s - D5m) / (DT61 + DT62) < 0.8. By restricting (D6s - D5m) / (DT61 + DT62) within a reasonable range, it is beneficial for the sixth lens to have a larger imaging surface and makes the spatial distribution of the sixth lens in the system more reasonable. Preferably, 0.03 < (D6s - D5m) / (DT61 + DT62) < 0.60.

[0071] In this embodiment, the plurality of spacer rings further includes a fifth auxiliary element located between the fifth spacer ring and the sixth lens and at least partially in contact with the image side surface of the fifth spacer ring. The inner diameter d5bs of the object side surface of the fifth auxiliary element and the perpendicular distance Yc61 from the inflection point on the object side surface of the sixth lens to the optical axis satisfy: 2.5 < d5bs / Yc61 < 4.0. By limiting d5bs / Yc61 within a reasonable range, it is possible to effectively use the fifth auxiliary element to prevent light rays from passing through the inflection position without affecting the imaging quality, thereby avoiding affecting the performance of the imaging system. Preferably, 2.7 < d5bs / Yc61 < 3.8.

[0072] In this embodiment, the plurality of spacer rings further includes a fifth auxiliary element located between the fifth spacer ring and the sixth lens and at least partially in contact with the image side surface of the fifth spacer ring. The inner diameter d5bs of the object side surface of the fifth auxiliary element, the perpendicular distance Yc61 from the inflection point on the object side surface of the sixth lens to the optical axis, and the effective focal length f6 of the sixth lens satisfy: 0.1 < (d5s - Yc61) / f6 < 1.5. By limiting (d5s - Yc61) / f6 within a reasonable range, it is possible to effectively control the step difference between the fifth lens and the sixth lens within a certain range, ensure the stability of the system, and thereby improve the imaging quality of the system. Preferably, 0.2 < (d5s - Yc61) / f6 < 1.4.

[0073] In this embodiment, the plurality of spacer rings further includes a second spacer ring located between the second lens and the third lens and at least partially in contact with the image side surface of the second lens. The outer diameter D2s of the object side surface of the second spacer ring, the maximum effective radius DT22 of the image side surface of the second lens, and the maximum effective radius DT31 of the object side surface of the third lens satisfy: 0.6 < (D2s - DT22*2) / (D2s - DT31*2) < 1.2. By limiting (D2s - DT22*2) / (D2s - DT31*2) within a reasonable range, it is possible to control the interception of the light rays emitted by the second lens by the second spacer ring and limit the number of incident light rays entering the third lens. Under the condition of ensuring the lens illuminance, the more light is blocked, the better the stray light is improved, and the higher the imaging quality of the lens is; at the same time, it is possible to ensure that the mating surfaces of the second lens, the third lens, and the second spacer ring coincide on the same straight line, and the larger the coincidence area, the better the system assembly stability. Preferably, 0.8 < (D2s - DT22*2) / (D2s - DT31*2) < 1.1.

[0074] In this embodiment, the effective focal length f of the optical imaging system, the field of view FOV of the optical imaging system, the minimum inner diameter ds of the lens barrel, and the inner diameter d2s of the object side surface of the second spacer ring satisfy: 3.0 < f * tan(FOV / 2) / (ds - d2s) < 4.5. By limiting f * tan(FOV / 2) / (ds - d2s) within a reasonable range, it is beneficial to ensure that the lens meets the normal shooting requirements. The minimum inner diameter ds of the front end portion of the lens barrel facing the object to be photographed should be greater than the diameter of the sectional circle corresponding to the FOV at this position (with a size of 2 * tan(FOV / 2) × VP, where VP is the distance from this position to the convergence point of the FOV on the optical axis), and the outer diameter of the object side end surface of the lens barrel should meet the assembly requirements; therefore, when designing the lens barrel, there should be no light blocking, and at the same time, it helps to ensure that the annular width of the object side end surface of the lens barrel is not too small, which can not only ensure normal shooting but also enable normal assembly. Preferably, 3.1 < f * tan(FOV / 2) / (ds - d2s) < 4.4.

[0075] In this embodiment, the plurality of spacer rings further includes a sixth auxiliary element located between the sixth spacer ring and the seventh lens and at least partially in contact with the image side surface of the sixth spacer ring, which can ensure the stability during the assembly of the sixth lens and the seventh lens, thereby ensuring the imaging quality of the system.

[0076] In this embodiment, the distance EP45 along the optical axis from the image side surface of the fourth spacer ring to the object side surface of the fifth spacer ring, the distance EP56 along the optical axis from the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring, the effective focal length f6 of the sixth lens, and the effective focal length f4 of the fourth lens satisfy: -20.0 mm < (EP45 + EP56) / (f6 / f4) < -10.0 mm. By limiting (EP45 + EP56) / (f6 / f4) within a reasonable range, when the optical power of the fourth lens is negative and the sixth lens has a positive optical power, it is beneficial to adjust the angles of the incident light and the outgoing light of the optical imaging system, effectively correct the chromatic aberration of the optical imaging system, improve the imaging quality of the optical imaging system, and improve the assembly stability at the large step position from the fourth lens to the sixth lens. Preferably, -19.0 mm < (EP45 + EP56) / (f6 / f4) < -11.0 mm.

[0077] In this embodiment, the curvature radius R12 of the image side of the sixth lens and the effective focal length f6 of the sixth lens satisfy: 0 < R12 / f6 < 20.0. The inner diameter d4m of the image side of the fourth spacer ring, the curvature radius R8 of the image side of the fourth lens, and the curvature radius R7 of the object side of the fourth lens satisfy: 0.1 mm < d4m / (R8 / R7) < 5.0 mm. By restricting R12 / f6 and d4m / (R8 / R7) within reasonable ranges, the field curvature contributions of the fourth lens and the sixth lens can be within a reasonable range, reducing the optical sensitivity between the object side of the fourth lens and the image side of the sixth lens. And by controlling the curvature radii of the object side and the image side of the fourth lens, it helps to improve the spherical aberration and astigmatism of the system, and at the same time improve the reflected stray light, thereby enhancing the imaging quality of the system. Preferably, 1.0 < R12 / f6 < 18.0 and 0.2 mm < d4m / (R8 / R7) < 4.8 mm.

[0078] Second Embodiment

[0079] As Figures 1 to 23 shown, the optical imaging system includes a lens group, a plurality of spacer rings, and a lens barrel. Along the object side to the image side of the optical imaging system, the optical imaging system sequentially includes a first lens to a seventh lens. The optical power of the first lens is positive, the optical power of the second lens is negative, the optical power of the third lens is positive, the optical power of the fourth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative. The plurality of spacer rings at least include a fourth spacer ring located between the fourth lens and the fifth lens and at least partially in contact with the image side of the fourth lens, a fifth spacer ring located between the fifth lens and the sixth lens and at least partially in contact with the image side of the fifth lens, and a sixth spacer ring located between the sixth lens and the seventh lens and at least partially in contact with the image side of the sixth lens. The lens barrel is used to accommodate the lens group and the plurality of spacer rings. Among them, the distance EP45 along the optical axis direction from the image side of the fourth spacer ring to the object side of the fifth spacer ring, the distance EP56 along the optical axis direction from the image side of the fifth spacer ring to the object side of the sixth spacer ring, the effective focal length f6 of the sixth lens, and the effective focal length f4 of the fourth lens satisfy: -20.0 mm < (EP45 + EP56) / (f6 / f4) < -10.0 mm. The curvature radius R7 of the object side of the fourth lens and the effective focal length f4 of the fourth lens satisfy: 0 < R7 / f4 < 0.8. The curvature radius R12 of the image side of the sixth lens and the effective focal length f6 of the sixth lens satisfy: 0 < R12 / f6 < 20.0. The inner diameter d4m of the image side of the fourth spacer ring, the curvature radius R8 of the image side of the fourth lens, and the curvature radius R7 of the object side of the fourth lens satisfy: 0.1 mm < d4m / (R8 / R7) < 5.0 mm.

[0080] The present application provides a seven-lens optical imaging system. The optical powers of the first lens, the third lens, and the sixth lens are positive, while the optical powers of the second lens, the fourth lens, and the seventh lens are negative. By reasonably controlling the positive and negative distribution of the optical powers of the respective lenses of the optical imaging system, and controlling -20.0 mm < (EP45 + EP56) / (f6 / f4) < -10.0 mm, 0 < R7 / f4 < 0.8, 0 < R12 / f6 < 20.0, the low-order aberrations of the optical imaging system are effectively balanced, the sensitivity to the tolerances of the fourth lens and the sixth lens is reduced, chromatic aberration is corrected, the field curvature contributions of the fourth lens and the sixth lens are within a reasonable range, and the optical sensitivity of the object side of the fourth lens and the image side of the sixth lens is reduced. However, this design results in a large step at the positions of the fourth to sixth lenses in the optical imaging system, which is likely to cause stray light problems. Affected by the thickness of the spacer ring, the more complex the spacer ring structure, the more complex the stray light state. The present application controls the inner diameter size of the fourth spacer ring and the curvature radii of the object side and the image side of the fourth lens, which helps to improve the spherical aberration and astigmatism of the system, and while ensuring the stable assembly of the fourth spacer ring group, improves the reflected stray light, thereby enhancing the imaging quality of the system.

[0081] Preferably, -19.0 mm < (EP45 + EP56) / (f6 / f4) < -11.0 mm.

[0082] Preferably, 0.05 < R7 / f4 < 0.70.

[0083] Preferably, 1.0 < R12 / f6 < 18.0.

[0084] Preferably, 0.2 mm < d4m / (R8 / R7) < 4.8 mm.

[0085] It should be noted that other conditional expressions in the first embodiment may also be included in this embodiment, which will not be elaborated here one by one.

[0086] The third embodiment

[0087] Such as Figures 1 to 23As shown, the optical imaging system includes a lens group, a plurality of spacer rings, and a lens barrel. Along the object side to the image side of the optical imaging system, the optical imaging system sequentially includes a first lens to a seventh lens. The optical power of the first lens is positive, the optical power of the second lens is negative, the optical power of the third lens is positive, the optical power of the fourth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative. The plurality of spacer rings at least include a fourth spacer ring located between the fourth lens and the fifth lens and at least partially in contact with the image side surface of the fourth lens, a fifth spacer ring located between the fifth lens and the sixth lens and at least partially in contact with the image side surface of the fifth lens, and a sixth spacer ring located between the sixth lens and the seventh lens and at least partially in contact with the image side surface of the sixth lens. The lens barrel is used to accommodate the lens group and the plurality of spacer rings. Among them, the distance EP45 along the optical axis direction from the image side surface of the fourth spacer ring to the object side surface of the fifth spacer ring, the distance EP56 along the optical axis direction from the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring, the effective focal length f6 of the sixth lens, and the effective focal length f4 of the fourth lens satisfy: -20.0mm < (EP45 + EP56) / (f6 / f4) < -10.0mm. The radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f4 of the fourth lens satisfy: 0 < R7 / f4 < 0.8. The radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f6 of the sixth lens satisfy: 0 < R12 / f6 < 20.0. The inner diameter d5s of the object side surface of the fifth spacer ring, the radius of curvature R10 of the image side surface of the fifth lens, and the radius of curvature R9 of the object side surface of the fifth lens satisfy: -10.0mm < d5s / (R10 / R9) < 10.0mm.

[0088] The present application provides a seven-lens optical imaging system. The optical powers of the first lens, the third lens, and the sixth lens are positive, while the optical powers of the second lens, the fourth lens, and the seventh lens are negative. By reasonably controlling the positive and negative distribution of the optical powers of the respective lenses of the optical imaging system, and controlling -20.0 mm < (EP45 + EP56) / (f6 / f4) < -10.0 mm, 0 < R7 / f4 < 0.8, 0 < R12 / f6 < 20.0, the low-order aberrations of the optical imaging system are effectively balanced, the sensitivity of the tolerances of the fourth and sixth lenses is reduced, chromatic aberration is corrected, the field curvature contributions of the fourth and sixth lenses are within a reasonable range, and the optical sensitivity of the object side of the fourth lens and the image side of the sixth lens is reduced. However, this design results in a large step difference at the positions of the fourth to sixth lenses of the optical imaging system, which easily causes stray light problems. Affected by the thickness of the spacer ring, the more complex the spacer ring structure, the more complex the stray light state. The present application controls the curvature radii of the object side and the image side of the fifth lens and the inner diameter size of the fifth spacer ring, further intercepts stray light while ensuring the stable assembly of the large step difference between the fifth lens and the sixth lens, improves the spherical aberration and astigmatism of the system, effectively controls the field curvature of the system, enhances the imaging quality, and at the same time makes the transition between the optical part and the structural part of the fifth lens smoother, which is beneficial to improving the processability of the fifth lens.

[0089] Preferably, -19.0 mm < (EP45 + EP56) / (f6 / f4) < -11.0 mm.

[0090] Preferably, 0.05 < R7 / f4 < 0.70.

[0091] Preferably, 1.0 < R12 / f6 < 18.0.

[0092] Preferably, -8.5 mm < d5s / (R10 / R9) < 9.0 mm.

[0093] It should be noted that other conditional expressions in the first embodiment may also be included in this embodiment, which will not be elaborated here one by one.

[0094] Fourth Embodiment

[0095] Such as Figures 1 to 23As shown, the optical imaging system includes a lens group, a plurality of spacer rings, and a lens barrel. Along the object side to the image side of the optical imaging system, the first lens to the seventh lens are sequentially included. The optical power of the first lens is positive, the optical power of the second lens is negative, the optical power of the third lens is positive, the optical power of the fourth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative. The plurality of spacer rings at least include a fourth spacer ring located between the fourth lens and the fifth lens and at least partially in contact with the image side of the fourth lens, a fifth spacer ring located between the fifth lens and the sixth lens and at least partially in contact with the image side of the fifth lens, and a sixth spacer ring located between the sixth lens and the seventh lens and at least partially in contact with the image side of the sixth lens. The lens barrel is used to accommodate the lens group and the plurality of spacer rings. Among them, the distance EP45 along the optical axis direction from the image side of the fourth spacer ring to the object side of the fifth spacer ring, the dispersion coefficient V4 of the fourth lens, the dispersion coefficient V5 of the fifth lens, and the effective focal length f4 of the fourth lens satisfy: -1.5 < EP45*(V4 + V5) / f4 < -0.1. The curvature radius R7 of the object side of the fourth lens and the effective focal length f4 of the fourth lens satisfy: 0 < R7 / f4 < 0.8. The curvature radius R12 of the image side of the sixth lens and the effective focal length f6 of the sixth lens satisfy: 0 < R12 / f6 < 20.0. The inner diameter d4m of the image side of the fourth spacer ring, the curvature radius R8 of the image side of the fourth lens, and the curvature radius R7 of the object side of the fourth lens satisfy: 0.1 mm < d4m / (R8 / R7) < 5.0 mm.

[0096] This application provides a seven-piece optical imaging system. The optical powers of the first lens, the third lens, and the sixth lens are positive, and the optical powers of the second lens, the fourth lens, and the seventh lens are negative. By reasonably controlling the positive and negative distribution of the optical powers of the respective lenses of the optical imaging system, and controlling -1.5 < EP45*(V4 + V5) / f4 < -0.1, 0 < R7 / f4 < 0.8, 0 < R12 / f6 < 20.0, the low-order aberrations of the optical imaging system are effectively balanced, the sensitivity of the tolerances of the fourth and sixth lenses is reduced, the chromatic aberration is corrected, the field curvature contributions of the fourth lens and the sixth lens are within a reasonable range, the optical sensitivity between the object side of the fourth lens and the image side of the sixth lens is reduced, and it is also helpful to control the edge thickness of the fifth lens and reduce the difficulty of forming the fifth lens. However, this design causes a large step difference at the positions of the fourth to sixth lenses of the optical imaging system, which is likely to cause stray light problems. Affected by the thickness of the spacer rings, the more complex the structure of the spacer rings, the more complex the stray light state. By controlling the inner diameter size of the fourth spacer ring and the curvature radii of the object side and the image side of the fourth lens, this application helps to improve the spherical aberration and astigmatism of the system, and while ensuring the stable assembly of the fourth spacer ring group, it improves the reflected stray light, thereby enhancing the imaging quality of the system.

[0097] Preferably, -1.45 <EP45*(V4+V5) / f4<-0.15。

[0098] Preferably, 0.05 <R7 / f4<0.70。

[0099] Preferably, 1.0 <R12 / f6<18.0。

[0100] Preferably, 0.2 mm <d4m / (R8 / R7)<4.8mm。

[0101] Optionally, the 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. The optical imaging system in the present application may use multiple lenses, such as the seven lenses mentioned above. By reasonably allocating the effective focal length, surface shape, center thickness of each lens, and axial distance between each lens, etc., the aperture of the optical imaging system can be effectively increased, the sensitivity of the lens can be reduced, and the processability of the lens can be improved, so that the optical imaging system is more conducive to production and processing and can be applied to portable electronic devices such as smart phones.

[0102] Figure 1 A schematic structural diagram of an optical imaging system of the present application is shown. Figure 1 Parameters such as d2s and d5m are also indicated in the figure to clearly and intuitively understand the meaning of the parameters. In order to facilitate the display of the optical imaging system structure and the specific surface shape, these parameters will no longer be reflected in the drawings when describing the specific embodiments later.

[0103] Wherein, Dis refers to the outer diameter of the object side of the ith isolating ring, dis refers to the inner diameter of the object side of the ith isolating ring, Dim refers to the outer diameter of the image side of the ith isolating ring, dim refers to the inner diameter of the image side of the ith isolating ring, CPi refers to the maximum thickness of the ith isolating ring, that is, the maximum distance from the object side of the ith isolating ring to the image side along the optical axis, EPij refers to the distance between the image side of the ith isolating ring and the object side of the jth isolating ring along the optical axis, wherein i and j are positive integers greater than or equal to 1. And d0s is the inner diameter of the object side end face of the lens barrel, and D0m is the outer diameter of the image side end face of the lens barrel. The maximum height L of the lens barrel refers to the maximum distance from the object side end face of the lens barrel to the image side end face of the lens barrel along the optical axis.

[0104] The following further describes examples of specific surface shapes and parameters of the optical imaging system applicable to the above-mentioned embodiments with reference to the accompanying drawings.

[0105] It should be noted that any one of the following embodiments 1 to 9 is applicable to all implementation methods of the present application.

[0106] Embodiment 1

[0107] like Figures 2 to 6 As shown, the optical imaging system of the first embodiment of the present application is described.

[0108] like Figure 2 As shown, the optical imaging system includes, from the object side to the image side, a first lens E1, a first isolation ring P1, a second lens E2, a second isolation ring P2, a third lens E3, a third isolation ring P3, a fourth lens E4, a fourth isolation ring P4, a fifth lens E5, a fifth isolation ring P5, a fifth auxiliary element P5b, a sixth lens E6, a sixth isolation ring P6, and a seventh lens E7. There is a large step difference between the fifth lens and the sixth lens, and two isolation rings are used to improve the assembly stability, and can further intercept edge stray light and improve the system image quality.

[0109] like Figure 2 As shown, the object side surface of the first lens is S1, the image side surface of the first lens is S2, the object side surface of the second lens is S3, the image side surface of the second lens is S4, the object side surface of the third lens is S5, the image side surface of the third lens is S6, the object side surface of the fourth lens is S7, the image side surface of the fourth lens is S8, the object side surface of the fifth lens is S9, the image side surface of the fifth lens is S10, the object side surface of the sixth lens is S11, the image side surface of the sixth lens is S12, the object side surface of the seventh lens is S13, and the image side surface of the seventh lens is S14.

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

[0111] Face number Surface type Radius of curvature thickness Refractive Index Abbe number Cone coefficient OBJ Spherical endless S1 Aspheric 3.4796 1.4885 1.55 56.14 0.0000 S2 Aspheric 16.3376 0.2789 0.0000 STO Spherical endless -0.1955 S3 Aspheric 5.9355 0.5000 1.67 20.37 0.0000 S4 Aspheric 3.6941 0.6002 0.0000 S5 Aspheric 11.3456 0.6807 1.57 37.40 1.0505 S6 Aspheric -90.8811 0.5674 0.0000 S7 Aspheric -17.3881 0.4100 1.67 20.37 25.2535 S8 Aspheric -389.6036 0.4759 0.0000 S9 Aspheric -7.3113 0.8038 1.57 37.40 6.9902 S10 Aspheric 13.6701 0.0298 0.0000 S11 Aspheric 2.0055 0.8410 1.55 56.14 -1.0000 S12 Aspheric 12.9919 0.9911 0.0000 S13 Aspheric 5.2885 0.5300 1.54 55.71 -1.0000 S14 Aspheric 2.1113 0.5782 -1.0000 S15 Spherical endless 0.2100 1.52 64.20 S16 Spherical endless 0.6000 S17 Spherical endless

[0112] Table 1

[0113] Table 1 also shows the object side surface S15 of the filter, the image side surface S16 of the filter, and the imaging surface S17.

[0114] In this embodiment, the first lens to the seventh lens are all aspherical lenses, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical formula:

[0115]

[0116] Among them, x is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c=1 / R, that is, the paraxial curvature c is the reciprocal of the curvature radius R in the above Table 1; k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface. The following Table 2 lists the high-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 surface in this embodiment.

[0117] Face number A4 A6 A8 A10 A12 A14 A16 S1 -4.5151E-02 -2.2802E-02 -1.0485E-02 -3.0525E-03 -8.7411E-04 1.3109E-04 1.0843E-04 S2 -1.6526E-02 1.1551E-04 -3.3009E-03 1.1493E-03 -2.9756E-04 2.2788E-04 -8.4023E-05 S3 -1.5036E-01 2.3657E-02 -2.6421E-03 1.0850E-03 -1.7718E-04 1.1624E-04 -1.6217E-05 S4 -1.4440E-01 1.0744E-02 -4.3851E-04 8.9008E-04 3.3377E-04 1.9803E-04 9.2909E-05 S5 -2.1125E-01 -2.5322E-02 -4.3300E-04 1.6271E-03 8.6786E-04 4.2678E-04 1.6633E-04 S6 -3.7597E-01 -2.7653E-02 2.7522E-03 9.0030E-05 1.4346E-04 -2.1814E-05 1.0578E-04 S7 -4.6801E-01 4.4468E-02 3.5900E-03 -8.6204E-03 4.7696E-04 -5.7601E-04 -3.8348E-04 S8 -4.0682E-01 2.2638E-02 1.0640E-02 -5.7227E-03 8.5539E-03 6.0066E-04 -1.6699E-05 S9 -3.1211E-02 -1.5477E-01 2.4769E-02 3.9089E-03 8.7716E-03 3.5860E-04 -3.8404E-04 S10 -3.2606E-01 3.2686E-02 3.3597E-02 5.3679E-03 -7.2563E-03 -4.5288E-03 7.4301E-04 S11 -2.9285E+00 3.5138E-01 1.1971E-01 -4.7420E-02 -1.7765E-02 1.5229E-02 -1.2489E-03 S12 -1.7224E+00 -1.9979E-01 5.7063E-02 4.7743E-02 -1.5692E-02 -1.0968E-02 1.3116E-02 S13 -3.6887E+00 1.2204E+00 -6.7426E-01 3.7271E-01 -1.8844E-01 5.5159E-02 2.2324E-03 S14 -8.3096E+00 2.0182E+00 -8.0207E-01 3.2058E-01 -1.4090E-01 6.7399E-02 -3.3615E-02 Face number A18 A20 A22 A22 A26 A28 A30 S1 1.1829E-04 4.4303E-06 -3.7389E-06 -2.3034E-05 -1.6184E-05 -1.6326E-05 4.7655E-06 S2 1.2500E-05 -1.7137E-05 1.3933E-05 1.0507E-05 1.0340E-05 5.8488E-06 1.0259E-05 S3 1.4145E-05 9.1983E-07 1.9381E-06 1.6513E-06 3.2426E-06 -5.0757E-06 -4.2616E-06 S4 3.8052E-05 2.3285E-05 7.3102E-06 5.9268E-06 -7.4406E-07 -6.1850E-07 -2.8289E-06 S5 9.1086E-05 1.8016E-05 1.7341E-05 -1.7410E-06 6.2182E-06 -1.9254E-06 4.0036E-07 S6 -1.1470E-05 9.4750E-06 -1.4489E-05 8.3770E-06 -5.1697E-06 3.1843E-06 -1.7445E-06 S7 -4.3687E-04 -1.5972E-04 -1.3273E-04 -4.9106E-05 -3.5512E-05 -5.8891E-06 -1.2511E-05 S8 -2.9070E-04 -8.6814E-05 -1.0113E-04 -1.4825E-05 -1.7120E-08 9.2455E-06 -2.1396E-07 S9 -3.1691E-04 -3.5287E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 1.2261E-03 3.8010E-04 -2.4524E-04 -1.7266E-04 -8.3897E-06 -5.6235E-07 0.0000E+00 S11 -5.6872E-03 3.8967E-03 2.3308E-03 -1.3435E-03 -8.5435E-04 1.3453E-04 2.2486E-04 S12 -3.7341E-03 -6.0877E-03 -2.0536E-04 2.8346E-03 2.3928E-03 -1.9881E-06 -2.4884E-04 S13 -1.1638E-02 -1.8404E-03 7.0914E-03 -3.4388E-03 1.4736E-03 9.6103E-05 2.5847E-05 S14 1.5513E-02 -6.8787E-03 3.7991E-03 -3.2098E-03 2.8408E-03 -9.1091E-04 1.8253E-04

[0118] Table 2

[0119] Figure 3 The axial chromatic aberration curve of the optical imaging system of the first embodiment is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical imaging system. Figure 4 The astigmatism curve of the optical imaging system of the first embodiment is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 5 The distortion curve of the optical imaging system of the first embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles. Figure 6 The magnification chromatic aberration curve of the optical imaging system of the first embodiment is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the optical imaging system.

[0120] according to Figures 3 to 6 It can be seen that the optical imaging system provided in the first embodiment can achieve good imaging quality.

[0121] Embodiment 2

[0122] The difference from the first embodiment is that the parameters of the lens barrel and the isolation ring are different.

[0123] like Figure 7 As shown, the optical imaging system of the second embodiment of the present application is described. For the sake of brevity, some descriptions similar to the first embodiment will be omitted.

[0124] The parameters of the first to seventh lenses of the optical imaging system in the second embodiment and the first embodiment, such as the curvature radius, the center thickness, and the spacing distance between the lenses, are the same, as shown in Table 1 and Table 2, but at least some of the parameters such as the lens barrel, the thickness of the isolation ring, the inner diameter of the isolation ring, the outer diameter of the isolation ring, and the distance between the isolation rings are different. Therefore, the imaging quality of the optical imaging system of this embodiment is as follows: Figures 3 to 6 shown.

[0125] like Figure 7As shown, a fifth auxiliary ring P5c is also provided between the fifth lens and the sixth lens. The fifth auxiliary ring is located between the fifth auxiliary element and the sixth lens and is in at least partial contact with the image side surface of the fifth auxiliary element, thereby further improving the assembly stability at large step difference positions and reducing the risk of the sixth lens being unstable and causing problems such as tilting and eccentricity.

[0126] Embodiment 3

[0127] The difference from the first embodiment is that the parameters of the lens barrel and the isolation ring are different.

[0128] like Figure 8 As shown, the optical imaging system of the third embodiment of the present application is described. For the sake of brevity, some descriptions similar to the first embodiment will be omitted.

[0129] The parameters of the first to seventh lenses of the optical imaging system in the third embodiment and the first embodiment, such as the curvature radius, center thickness, and the spacing distance between the lenses, are the same, as shown in Table 1 and Table 2, but at least some of the parameters such as the lens barrel, the thickness of the isolation ring, the inner diameter of the isolation ring, the outer diameter of the isolation ring, and the distance between the isolation rings are different. Therefore, the imaging quality of the optical imaging system of this embodiment is as follows: Figures 3 to 6 shown.

[0130] Embodiment 4

[0131] The difference from the first embodiment is that the parameters of the lens barrel P0, the isolation ring and the lens are different.

[0132] like Figures 9 to 13 As shown, the optical imaging system of the fourth embodiment of the present application is described.

[0133] like Fig. 9 As shown, the optical imaging system includes, from the object side to the image side, a first lens E1, a first isolation ring P1, a second lens E2, a second isolation ring P2, a third lens E3, a third isolation ring P3, a fourth lens E4, a fourth isolation ring P4, a fifth lens E5, a fifth isolation ring P5, a fifth auxiliary element P5b, a sixth lens E6, a sixth isolation ring P6, a sixth auxiliary element P6b, and a seventh lens E7. There is a large step difference between the fifth lens and the sixth lens, and between the sixth lens and the seventh lens. Two isolation rings are used between two adjacent lenses to improve the assembly stability, and can further intercept edge stray light and improve the system image quality.

[0134] like Fig. 9As shown, the object side surface of the first lens is S1, the image side surface of the first lens is S2, the object side surface of the second lens is S3, the image side surface of the second lens is S4, the object side surface of the third lens is S5, the image side surface of the third lens is S6, the object side surface of the fourth lens is S7, the image side surface of the fourth lens is S8, the object side surface of the fifth lens is S9, the image side surface of the fifth lens is S10, the object side surface of the sixth lens is S11, the image side surface of the sixth lens is S12, the object side surface of the seventh lens is S13, and the image side surface of the seventh lens is S14.

[0135] Table 3 shows a basic structural parameter table of the optical imaging system of Example 4, wherein the units of the curvature radius, thickness / distance, and effective focal length are all millimeters (mm).

[0136] Face number Surface type Radius of curvature thickness Refractive Index Abbe number Cone coefficient OBJ Spherical endless S1 Aspheric 3.6706 1.4586 1.55 56.14 0.0000 S2 Aspheric 209.8354 0.2586 0.0000 STO Spherical endless -0.2352 S3 Aspheric 8.0528 0.5000 1.67 20.37 0.0000 S4 Aspheric 3.9015 0.6497 0.0000 S5 Aspheric 8.7781 0.7000 1.57 37.40 2.6771 S6 Aspheric 30.3223 0.6442 0.0000 S7 Aspheric -16.4460 0.4100 1.67 20.37 29.0900 S8 Aspheric -19.2068 0.2337 0.0000 S9 Aspheric -10.1072 0.6043 1.57 37.40 10.3196 S10 Aspheric -8.7281 0.6000 0.0000 S11 Aspheric 4.6963 0.8048 1.55 56.14 0.0000 S12 Aspheric 14.9590 0.8514 0.0000 S13 Aspheric 4.5859 0.5300 1.54 55.71 -1.0000 S14 Aspheric 1.8537 0.4888 -1.0000 S15 Spherical endless 0.2310 1.52 64.20 S16 Spherical endless 0.6600 S17 Spherical endless

[0137] Table 3

[0138] Table 3 also shows the object side surface S15 of the filter, the image side surface S16 of the filter, and the imaging surface S17.

[0139] In this embodiment, the first lens to the seventh lens are all aspherical lenses, and the surface shape of each aspherical lens can be defined by, but not limited to, formula (1) in Embodiment 1. Table 4 below lists the high-order coefficients of each aspherical mirror surface that can be used in this embodiment.

[0140]

[0141]

[0142] Table 4

[0143] Fig.10 The axial chromatic aberration curve of the optical imaging system of the fourth embodiment is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical imaging system. Fig.11 The astigmatism curve of the optical imaging system of the fourth embodiment is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Fig.12 The distortion curve of the optical imaging system of the fourth embodiment is shown, which represents the distortion magnitude values ​​corresponding to different field angles. Fig.13 The magnification chromatic aberration curve of the optical imaging system of Example 4 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the optical imaging system.

[0144] according to Figures 10 to 13 It can be seen that the optical imaging system provided in the fourth embodiment can achieve good imaging quality.

[0145] Embodiment 5

[0146] The difference from the fourth embodiment is that the parameters of the lens barrel P0 and the isolation ring are different.

[0147] like Fig.14 As shown, the optical imaging system of the fifth embodiment of the present application is described. For the sake of brevity, some descriptions similar to the fourth embodiment will be omitted.

[0148] The parameters of the curvature radius, center thickness and the spacing distance between the first to seventh lenses of the optical imaging system in the fifth embodiment and the fourth embodiment are the same, as shown in Table 3 and Table 4, but at least some of the parameters such as the lens barrel P0, the thickness of the isolation ring, the inner diameter of the isolation ring, the outer diameter of the isolation ring and the distance between the isolation rings are different. Therefore, the imaging quality of the optical imaging system of this embodiment is as follows: Figures 10 to 13 shown.

[0149] like Fig.14 As shown, a fifth auxiliary ring P5c is also provided between the fifth lens and the sixth lens. The fifth auxiliary ring is located between the fifth auxiliary element and the sixth lens and is in at least partial contact with the image side surface of the fifth auxiliary element, thereby further improving the assembly stability at large step difference positions and reducing the risk of the sixth lens being unstable and causing problems such as tilting and eccentricity.

[0150] Embodiment 6

[0151] The difference from the fourth embodiment is that the parameters of the lens barrel P0 and the isolation ring are different.

[0152] like Fig.15 As shown, the optical imaging system of the sixth embodiment of the present application is described. For the sake of brevity, some descriptions similar to the fourth embodiment will be omitted.

[0153] The parameters of the first to seventh lenses of the optical imaging system in the sixth embodiment and the fourth embodiment are the same, such as the curvature radius, center thickness, and the spacing distance between the lenses, as shown in Table 3 and Table 4, but at least some of the parameters such as the lens barrel P0, the thickness of the isolation ring, the inner diameter of the isolation ring, the outer diameter of the isolation ring, and the distance between the isolation rings are different. Therefore, the imaging quality of the optical imaging system of this embodiment is as follows: Figures 10 to 13 shown.

[0154] like Fig.15 As shown, a fifth auxiliary ring P5c is further provided between the fifth lens and the sixth lens, and a sixth auxiliary ring P6c is further provided between the sixth lens and the seventh lens. The fifth auxiliary ring is located between the fifth auxiliary element and the sixth lens and is in at least partial contact with the image side surface of the fifth auxiliary element. The sixth auxiliary ring is located between the sixth auxiliary element and the seventh lens and is in at least partial contact with the image side surface of the sixth auxiliary element, which further improves the assembly stability of the large step difference positions from the fifth lens to the seventh lens and reduces the risk of the sixth lens and the seventh lens being unstable and causing problems such as tilt and eccentricity.

[0155] Embodiment 7

[0156] The difference from the first embodiment is that the parameters of the lens barrel P0, the isolation ring and the lens are different.

[0157] like Figures 16 to 20 As shown, the optical imaging system of embodiment 7 of the present application is described.

[0158] like Fig.16 As shown, the optical imaging system includes, from the object side to the image side, a first lens E1, a first isolation ring P1, a second lens E2, a second isolation ring P2, a third lens E3, a third isolation ring P3, a fourth lens E4, a fourth isolation ring P4, a fifth lens E5, a fifth isolation ring P5, a fifth auxiliary element P5b, a sixth lens E6, a sixth isolation ring P6, a sixth auxiliary element P6b, a seventh lens E7, and a seventh isolation ring P7. Among them, there is a large step difference between the fifth lens and the sixth lens, and between the sixth lens and the seventh lens. Two isolation rings are used between two adjacent lenses to improve the assembly stability, and can further intercept edge stray light and improve the system image quality. The seventh isolation ring can further ensure the assembly stability of the seventh lens and avoid the problem of tilting and shaking.

[0159] like Fig.16 As shown, the object side surface of the first lens is S1, the image side surface of the first lens is S2, the object side surface of the second lens is S3, the image side surface of the second lens is S4, the object side surface of the third lens is S5, the image side surface of the third lens is S6, the object side surface of the fourth lens is S7, the image side surface of the fourth lens is S8, the object side surface of the fifth lens is S9, the image side surface of the fifth lens is S10, the object side surface of the sixth lens is S11, the image side surface of the sixth lens is S12, the object side surface of the seventh lens is S13, and the image side surface of the seventh lens is S14.

[0160] Table 5 shows a basic structural parameter table of the optical imaging system of Example 7, wherein the units of the radius of curvature, thickness / distance, and effective focal length are all millimeters (mm).

[0161]

[0162]

[0163] Table 5

[0164] Table 5 also gives the object side surface S15 of the filter, the image side surface S16 of the filter, and the imaging surface S17.

[0165] In this embodiment, the first lens to the seventh lens are all aspherical lenses, and the surface shape of each aspherical lens can be defined by, but not limited to, formula (1) in Embodiment 1. Table 6 below lists the high-order coefficients of each aspherical mirror surface that can be used in this embodiment.

[0166]

[0167]

[0168] Table 6

[0169] Fig.17 The axial chromatic aberration curve of the optical imaging system of the seventh embodiment is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical imaging system. Fig.18 The astigmatism curve of the optical imaging system of Example 7 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Fig.19 The distortion curve of the optical imaging system of the seventh embodiment is shown, which represents the distortion magnitude values ​​corresponding to different field angles. Fig. 20 The magnification chromatic aberration curve of the optical imaging system of Example 7 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the optical imaging system.

[0170] according to Figures 17 to 20 It can be seen that the optical imaging system provided in the seventh embodiment can achieve good imaging quality.

[0171] Embodiment 8

[0172] The difference from the seventh embodiment is that the parameters of the lens barrel P0 and the isolation ring are different.

[0173] like Fig.21 As shown, an optical imaging system of the eighth embodiment of the present application is described. For the sake of brevity, some descriptions similar to those of the seventh embodiment will be omitted.

[0174] The parameters of the optical imaging system of the eighth embodiment and the seventh embodiment, such as the curvature radius, the center thickness and the spacing distance between the first lens to the seventh lens, are the same as shown in Table 5 and Table 6, but at least some of the parameters such as the lens barrel P0, the thickness of the isolation ring, the inner diameter of the isolation ring, the outer diameter of the isolation ring and the distance between the isolation rings are different. Therefore, the imaging quality of the optical imaging system of this embodiment is as follows: Figures 17 to 20 shown.

[0175] like Fig.21 As shown, a fifth auxiliary ring P5c is also provided between the fifth lens and the sixth lens. The fifth auxiliary ring is located between the fifth auxiliary element and the sixth lens and is in at least partial contact with the image side surface of the fifth auxiliary element, thereby further improving the assembly stability at large step difference positions and reducing the risk of the sixth lens being unstable and causing problems such as tilting and eccentricity.

[0176] Embodiment 9

[0177] The difference from the seventh embodiment is that the parameters of the lens barrel P0 and the isolation ring are different.

[0178] like Fig. 22 As shown, the optical imaging system of the ninth embodiment of the present application is described. For the sake of brevity, some descriptions similar to those of the seventh embodiment will be omitted.

[0179] The parameters of the optical imaging system of the ninth embodiment and the seventh embodiment, such as the curvature radius, the center thickness and the spacing distance between the lenses, are the same, as shown in Table 5 and Table 6, but at least some of the parameters such as the lens barrel P0, the thickness of the isolation ring, the inner diameter of the isolation ring, the outer diameter of the isolation ring and the distance between the isolation rings are different. Therefore, the imaging quality of the optical imaging system of this embodiment is as follows: Figures 17 to 20 shown.

[0180] like Fig. 22 As shown, a fifth auxiliary ring P5c is further provided between the fifth lens and the sixth lens, and a sixth auxiliary ring P6c is further provided between the sixth lens and the seventh lens. The fifth auxiliary ring is located between the fifth auxiliary element and the sixth lens and is in at least partial contact with the image side surface of the fifth auxiliary element. The sixth auxiliary ring is located between the sixth auxiliary element and the seventh lens and is in at least partial contact with the image side surface of the sixth auxiliary element, which further improves the assembly stability of the large step difference positions from the fifth lens to the seventh lens and reduces the risk of the sixth lens and the seventh lens being unstable and causing problems such as tilt and eccentricity.

[0181] In summary, embodiments 1 to 9 respectively satisfy the relationship shown in Table 7.

[0182] Conditional / Example 1 2 3 4 5 6 7 8 9 EP56 / (R11 / f6) 2.39 2.39 2.39 1.65 1.65 1.65 1.81 1.81 1.81 f6 / d6s-f7 / d6m 1.18 1.18 1.18 1.77 1.87 1.87 1.08 1.08 1.19 R7 / f4 0.64 0.64 0.64 0.09 0.09 0.09 0.48 0.48 0.48 d5s / (R10 / R9) -3.66 -3.22 -3.22 8.10 7.47 7.47 -6.54 -6.07 -6.07 d5m / R12 0.68 0.46 0.46 0.60 0.43 0.43 0.19 0.13 0.13 EP45*(V4+V5) / f4 -1.28 -1.28 -1.28 -0.17 -0.17 -0.17 -1.03 -1.03 -1.03 N4*EP34 / (R8 / f) -0.02 -0.02 -0.02 -0.49 -0.49 -0.49 -0.17 -0.17 -0.17 f6 / L 0.49 0.49 0.49 1.42 1.42 1.42 0.44 0.44 0.44 T56 / (CP5+EP56) 0.01 0.03 0.03 0.40 0.92 0.92 0.02 0.04 0.04 [(d2s-d1s)*f1] / [(d3s-d2s)*f3] 0.48 0.48 0.48 0.34 0.34 0.34 0.51 0.51 0.51 EP01 / CT1 1.25 1.25 1.25 1.24 1.24 1.24 1.20 1.20 1.20 (f56-T56-CP6) / L 0.95 0.95 0.95 1.05 1.17 1.17 0.85 0.85 0.91 EP01 / |SAGH11| 1.17 1.16 1.17 1.19 1.19 1.20 1.14 1.14 1.14 (D6s-D5m) / (DT61+DT62) 0.13 0.51 0.49 0.07 0.30 0.30 0.21 0.41 0.45 d5bs / Yc61 3.50 2.97 2.93 3.63 2.90 2.90 3.47 2.98 2.98 (d5s-Yc61) / f6 1.07 0.87 0.87 0.38 0.33 0.33 1.14 1.01 1.01 (D2s-DT22*2) / (D2s-DT31*2) 0.99 0.99 0.99 1.03 1.03 1.03 1.00 1.00 1.00 f*tan(FOV / 2) / (ds-d2s) 3.24 3.24 3.24 4.04 4.04 4.04 3.41 3.41 3.41 (EP45+EP56) / (f6 / f4) -11.23 -11.23 -11.23 -17.78 -17.78 -17.78 -11.60 -11.60 -11.60 R12 / f6 3.07 3.07 3.07 1.23 1.23 1.23 11.78 11.78 11.78 d4m / (R8 / R7) 0.22 0.22 0.22 4.54 4.54 4.54 1.44 1.44 1.44

[0183] Table 7

[0184] Table 8 gives some parameters of the optical imaging systems of Embodiments 1 to 9.

[0185] Example / Basic Data d1s d2s d3s d5s d5m EP34 EP45 1 4.4080 3.9032 4.3606 6.8524 8.8426 0.7030 0.6056 2 4.4080 3.9032 4.3606 6.0133 6.0133 0.7030 0.6056 3 4.4080 3.9032 4.3606 6.0133 6.0133 0.7030 0.6056 4 4.6224 4.1544 4.5879 6.9921 8.9823 0.7561 0.5526 5 4.6224 4.1544 4.5879 6.4498 6.4498 0.7561 0.5526 6 4.6224 4.1544 4.5879 6.4498 6.4498 0.7561 0.5526 7 4.4439 3.8796 4.3133 6.8976 8.8878 0.7561 0.5526 8 4.4439 3.8796 4.3133 6.4045 6.4045 0.7561 0.5526 9 4.4439 3.8796 4.3133 6.4045 6.4045 0.7561 0.5526 Example / Basic Data CP5 EP56 CP6 L d5bs |SAGH11| ds 1 1.0260 1.1337 0.0220 8.5542 8.1908 1.5929 5.5926 2 0.0180 1.1337 0.0220 8.5542 6.9523 1.5976 5.5926 3 0.0180 1.1337 0.0220 8.5542 6.8524 1.5938 5.5926 4 0.8632 0.6360 1.0499 8.6209 8.7545 1.5151 5.6441 5 0.0180 0.6360 0.0180 8.6209 6.9921 1.5151 5.6441 6 0.0180 0.6360 0.0180 8.6209 6.9921 1.5043 5.6441 7 0.8632 0.9523 0.5712 9.0655 8.0403 1.5721 5.4818 8 0.0180 0.9523 0.5712 9.0655 6.8976 1.5721 5.4818 9 0.0180 0.9523 0.0180 9.0655 6.8976 1.5721 5.4818

[0186] Table 8

[0187] Table 9 gives some optical parameters of the first lens to the seventh lens of the optical imaging system of Embodiments 1 to 9.

[0188] Basic data / Example 1 2 3 4 5 6 7 8 9 f1(mm) 7.78 7.78 7.78 6.83 6.83 6.83 7.59 7.59 7.59 f2(mm) -16.11 -16.11 -16.11 -11.93 -11.93 -11.93 -16.45 -16.45 -16.45 f3(mm) 17.74 17.74 17.74 21.43 21.43 21.43 19.52 19.52 19.52 f4(mm) -27.32 -27.32 -27.32 -182.50 -182.50 -182.50 -31.07 -31.07 -31.07 f5(mm) -8.24 -8.24 -8.24 96.84 96.84 96.84 -7.27 -7.27 -7.27 f6(mm) 4.23 4.23 4.23 12.20 12.20 12.20 4.03 4.03 4.03 f7(mm) -6.95 -6.95 -6.95 -6.22 -6.22 -6.22 -7.02 -7.02 -7.02 f(mm) 7.30 7.30 7.30 7.51 7.51 7.51 7.27 7.27 7.27 Yc61(mm) 2.3 2.3 2.3 2.4 2.4 2.4 2.3 2.3 2.3 FOV(°) 73.68 73.68 73.68 77.43 77.43 77.43 73.88 73.88 73.88

[0189] Table 9

[0190] The present application also provides an imaging device, whose electronic photosensitive element can be a photosensitive 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 in a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging system described above.

[0191] Obviously, the embodiments described above are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0192] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0193] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0194] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An optical imaging system, characterized in that: include: A lens group, wherein the optical imaging system includes, from the object side to the image side of the optical imaging system, a first lens to a seventh lens in sequence, wherein the first lens has a positive optical focal power, the second lens has a negative optical focal power, the third lens has a positive optical focal power, the fourth lens has a negative optical focal power, the sixth lens has a positive optical focal power, and the seventh lens has a negative optical focal power; a plurality of isolation rings, the plurality of isolation rings at least comprising a fourth isolation ring located between the fourth lens and the fifth lens and at least partially in contact with the image side surface of the fourth lens, a fifth isolation ring located between the fifth lens and the sixth lens and at least partially in contact with the image side surface of the fifth lens, and a sixth isolation ring located between the sixth lens and the seventh lens and at least partially in contact with the image side surface of the sixth lens; A lens barrel, the lens barrel being used to accommodate the lens group and the plurality of isolation rings; The curvature radius R7 of the object side surface of the fourth lens and the effective focal length f4 of the fourth lens satisfy the following relationship: <R7 / f4<0.8; The distance EP56 from the image side surface of the fifth isolation ring to the object side surface of the sixth isolation ring along the optical axis direction of the optical imaging system, the curvature radius R11 of the object side surface of the sixth lens, and the effective focal length f6 of the sixth lens satisfy: 1.5 mm <EP56 / (R11 / f6)<2.5mm; The effective focal length f6 of the sixth lens, the inner diameter d6s of the object side surface of the sixth isolation ring, the effective focal length f7 of the seventh lens, and the inner diameter d6m of the image side surface of the sixth isolation ring satisfy the following conditions: 1.0 <f6 / d6s-f7 / d6m<2.0。 2. The optical imaging system according to claim 1, characterized in that: The inner diameter d5s of the object side surface of the fifth isolation ring, the curvature radius R10 of the image side surface of the fifth lens, and the curvature radius R9 of the object side surface of the fifth lens satisfy: -10.0mm <d5s / (R10 / R9)<10.0mm。 3. The optical imaging system according to claim 1, characterized in that: The inner diameter d5m of the image side surface of the fifth isolation ring and the curvature radius R12 of the image side surface of the sixth lens satisfy: <d5m / R12<1.0。 4. The optical imaging system according to claim 1, characterized in that: The distance EP45 from the image side surface of the fourth isolation ring to the object side surface of the fifth isolation ring along the optical axis, the dispersion coefficient V4 of the fourth lens, the dispersion coefficient V5 of the fifth lens, and the effective focal length f4 of the fourth lens satisfy: -1.5 <EP45*(V4+V5) / f4<-0.1。 5. The optical imaging system according to claim 1, characterized in that: The plurality of isolation rings also include a third isolation ring located between the third lens and the fourth lens and at least partially in contact with the image side surface of the third lens, and the refractive index N4 of the fourth lens, the distance EP34 from the image side surface of the third isolation ring to the object side surface of the fourth isolation ring along the optical axis direction, the curvature radius R8 of the image side surface of the fourth lens, and the effective focal length f of the optical imaging system satisfy: -1.0 mm <N4*EP34 / (R8 / f)<0mm。 6. The optical imaging system according to claim 1, characterized in that: The effective focal length f6 of the sixth lens and the height L of the lens barrel satisfy: 0.2 < f6 / L < 2.

0. The air gap T56 between the fifth lens and the sixth lens on the optical axis, the maximum thickness CP5 of the fifth spacer along the optical axis direction, and the distance EP56 from the image side of the fifth spacer to the object side of the sixth spacer along the optical axis direction satisfy: 0 < T56 / (CP5 + EP56) < 1.

0.

7. The optical imaging system according to claim 1, characterized in that: The plurality of spacers further includes a first spacer located between the first lens and the second lens and at least partially in contact with the image side of the first lens, a second spacer located between the second lens and the third lens and at least partially in contact with the image side of the second lens, and a third spacer located between the third lens and the fourth lens and at least partially in contact with the image side of the third lens. The inner diameter of the object side of the second spacer is the smallest among the inner diameters of the object sides of the first spacer to the sixth spacer. The inner diameter d2s of the object side of the second spacer, the inner diameter d1s of the object side of the first spacer, the effective focal length f1 of the first lens, the inner diameter d3s of the object side of the third spacer, the inner diameter d2s of the object side of the second spacer, and the effective focal length f3 of the third lens satisfy: 0 < [(d2s - d1s) * f1] / [(d3s - d2s) * f3] < 1.

0.

8. The optical imaging system according to claim 1, characterized in that: The plurality of spacers further includes a first spacer located between the first lens and the second lens and at least partially in contact with the image side of the first lens. The distance EP01 from the object side end face of the lens barrel to the object side of the first spacer along the optical axis direction and the central thickness CT1 of the first lens on the optical axis satisfy: 1.0 < EP01 / CT1 < 1.

5.

9. The optical imaging system according to claim 1, characterized in that: The combined focal length f56 of the fifth lens and the sixth lens, the air gap T56 between the fifth lens and the sixth lens on the optical axis, the maximum thickness CP6 of the sixth spacer along the optical axis direction, and the height L of the lens barrel satisfy: 0.5 < (f56 - T56 - CP6) / L < 1.

5.

10. The optical imaging system according to any one of claims 1 to 9, characterized in that: The plurality of spacers further includes a first spacer located between the first lens and the second lens and at least partially in contact with the image side of the first lens. The distance EP01 from the object side end face of the lens barrel to the object side of the first spacer along the optical axis direction and the axial distance SAGH11 from the intersection of the object side of the first lens and the optical axis to the vertex of the effective radius of the object side of the first lens satisfy: 1.0 < EP01 / |SAGH11| < 1.

5.

11. The optical imaging system according to any one of claims 1 to 9, characterized in that: The outer diameter D6s of the object side of the sixth spacer, the outer diameter D5m of the image side of the fifth spacer, the maximum effective radius DT61 of the object side of the sixth lens, and the maximum effective radius DT62 of the image side of the sixth lens satisfy: 0 < (D6s - D5m) / (DT61 + DT62) < 0.

8.

12. The optical imaging system according to any one of claims 1 to 9, characterized in that: The multiple spacer rings further include a fifth auxiliary element located between the fifth spacer ring and the sixth lens and at least partially in contact with the image side surface of the fifth spacer ring. The inner diameter d5bs of the object side surface of the fifth auxiliary element and the perpendicular distance Yc61 from the inflection point on the object side surface of the sixth lens to the optical axis satisfy: 2.5 < d5bs / Yc61 < 4.

0.

13. The optical imaging system according to any one of claims 1 to 9, characterized in that: The multiple spacer rings further include a fifth auxiliary element located between the fifth spacer ring and the sixth lens and at least partially in contact with the image side surface of the fifth spacer ring. The inner diameter d5bs of the object side surface of the fifth auxiliary element, the perpendicular distance Yc61 from the inflection point on the object side surface of the sixth lens to the optical axis, and the effective focal length f6 of the sixth lens satisfy: 0.1 < (d5s - Yc61) / f6 < 1.

5.

14. The optical imaging system according to any one of claims 1 to 9, characterized in that: The multiple spacer rings further include a second spacer ring located between the second lens and the third lens and at least partially in contact with the image side surface of the second lens. The outer diameter D2s of the object side surface of the second spacer ring, the maximum effective radius DT22 of the image side surface of the second lens, and the maximum effective radius DT31 of the object side surface of the third lens satisfy: 0.6 < (D2s - DT22*2) / (D2s - DT31*2) < 1.

2.

15. The optical imaging system according to any one of claims 1 to 9, characterized in that: The multiple spacer rings further include a second spacer ring located between the second lens and the third lens and at least partially in contact with the image side surface of the second lens. The effective focal length f of the optical imaging system, the field of view FOV of the optical imaging system, the minimum inner diameter ds of the lens barrel, and the inner diameter d2s of the object side surface of the second spacer ring satisfy: 3.0 < f*tan(FOV / 2) / (ds - d2s) < 4.

5.

16. The optical imaging system according to any one of claims 1 to 9, characterized in that: The multiple spacer rings further include a sixth auxiliary element located between the sixth spacer ring and the seventh lens and at least partially in contact with the image side surface of the sixth spacer ring.

17. The optical imaging system according to any one of claims 1 to 9, characterized in that: The distance EP45 from the image side surface of the fourth spacer ring to the object side surface of the fifth spacer ring along the optical axis direction, the distance EP56 from the image side surface of the fifth spacer ring to the object side surface of the sixth spacer ring along the optical axis direction, the effective focal length f6 of the sixth lens, and the effective focal length f4 of the fourth lens satisfy: -20.0 mm < (EP45 + EP56) / (f6 / f4) < -10.0 mm.

18. The optical imaging system according to any one of claims 1 to 9, characterized in that: The radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f6 of the sixth lens satisfy: 0 < R12 / f6 < 20.

0. The inner diameter d4m of the image side surface of the fourth spacer ring, the radius of curvature R8 of the image side surface of the fourth lens, and the radius of curvature R7 of the object side surface of the fourth lens satisfy: 0.1 mm < d4m / (R8 / R7) < 5.0 mm.

Images