CN114578514A

CN114578514A - Optical imaging system

Info

Publication number: CN114578514A
Application number: CN202210229001.8A
Authority: CN
Inventors: 娄琪琪; 黄林; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2022-03-08
Filing date: 2022-03-08
Publication date: 2022-06-03
Anticipated expiration: 2042-03-08
Also published as: CN114578514B

Abstract

The invention provides an optical imaging system, comprising in order from an object side to an image side: a first lens having an optical power; a second lens having an optical power; a third lens having optical power; a fourth lens having a refractive power, a surface of the fourth lens in the vicinity of an object-side optical axis being a convex surface; a fifth lens having a refractive power, a surface of the fifth lens near an image side optical axis being a convex surface; a sixth lens having negative refractive power, a surface of the sixth lens in the vicinity of an object-side optical axis being a concave surface; wherein, the f-number Fno of the optical imaging system satisfies: fno < 1.7; the effective focal length f5 of the fifth lens and half semisum-Fov of the maximum field angle of the optical imaging system satisfy that: 4mm < f5 star (semi-Fov) <6.5 mm; the distance TTL along the optical axis between the surface of the first lens near the optical axis of the object side and the imaging surface of the optical imaging system and the air gap T56 on the optical axis between the fifth lens and the sixth lens satisfy that: 4< TTL/T56< 6. The invention solves the problem of poor imaging quality of the optical imaging system in the prior art.

Description

Optical imaging system

Technical Field

The invention relates to the technical field of optical imaging equipment, in particular to an optical imaging system.

Background

Along with the development of mobile terminals, the dependence of people on the mobile terminals is higher and higher, meanwhile, the requirements of people on lenses carried on the mobile terminals are also higher and higher, users expect that the imaging of the mobile terminals can be clearer, and the imaging can be clearer in different environments, so that the requirement that the image quality of the mobile terminals cannot be met by the existing imaging system is caused.

That is, the optical imaging system in the prior art has a problem of poor imaging quality.

Disclosure of Invention

The invention mainly aims to provide an optical imaging system to solve the problem that the optical imaging system in the prior art is poor in imaging quality.

In order to achieve the above object, according to an aspect of the present invention, there is provided an optical imaging system including, in order from an object side to an image side: a first lens having an optical power; a second lens having an optical power; a third lens having optical power; a fourth lens having a refractive power, a surface of the fourth lens in the vicinity of an object-side optical axis being a convex surface; a fifth lens having a refractive power, a surface of the fifth lens near an image side optical axis being a convex surface; a sixth lens having negative refractive power, a surface of the sixth lens in the vicinity of an object-side optical axis being a concave surface; wherein, the f-number Fno of the optical imaging system satisfies: fno < 1.7; the effective focal length f5 of the fifth lens and half semisum-Fov of the maximum field angle of the optical imaging system satisfy that: 4mm < f5 tan (semi-Fov) <6.5 mm; the distance TTL along the optical axis between the surface of the first lens near the optical axis of the object side and the imaging surface of the optical imaging system and the air gap T56 on the optical axis between the fifth lens and the sixth lens satisfy that: 4< TTL/T56< 6.

Further, the air gap T56 between the fifth lens and the sixth lens on the optical axis and the effective focal length f of the optical imaging system satisfy: 3< f/T56< 5.

Further, a distance TTL along the optical axis from the surface of the first lens in the vicinity of the object side optical axis to the imaging plane of the optical imaging system, a sum Σ CT of center thicknesses of all lenses of the first lens to the sixth lens, and a half ImgH of a diagonal length of the effective pixel region on the imaging plane satisfy: 0.5< (TTL-sigma CT)/ImgH < 1.5.

Further, the optical imaging system satisfies the following relationship between the f-number Fno and half of the diagonal length ImgH of the effective pixel area on the imaging plane: 7.5mm < Fno ImgH <9 mm.

Further, the effective focal length f5 of the fifth lens and the effective focal length f of the optical imaging system satisfy: 0.4< f5/f < 1.5.

Further, a distance TTL along the optical axis from the surface of the first lens in the vicinity of the object side optical axis to the imaging surface of the optical imaging system, an effective focal length f of the optical imaging system, and an effective focal length f6 of the sixth lens satisfy: 3.0< TTL/(f + f6) < 6.0.

Further, a combined focal length f123 of the first lens, the second lens and the third lens and a combined focal length f2345 of the second lens, the third lens, the fourth lens and the fifth lens satisfy: 1.0< f123/f2345< 2.5.

Further, a radius of curvature R10 of a surface of the fifth lens in the vicinity of the image-side optical axis and a radius of curvature R11 of a surface of the sixth lens in the vicinity of the object-side optical axis satisfy: -0.5< (R10-R11)/(R10+ R11) < 0.5.

Further, the center thickness CT1 of the first lens, the air gap T12 of the first lens and the second lens on the optical axis, the center thickness CT2 of the second lens, the air gap T23 of the second lens and the third lens on the optical axis, and the center thickness CT3 of the third lens satisfy: 6.0< (CT1+ T12+ CT2+ T23+ CT3)/CT2< 8.5.

Further, an on-axis distance SAG51 between an intersection point of a surface of the fifth lens in the vicinity of the object side optical axis and the optical axis to an effective radius vertex of the surface of the fifth lens in the vicinity of the object side optical axis, an on-axis distance SAG61 between an intersection point of a surface of the sixth lens in the vicinity of the object side optical axis and the optical axis to an effective radius vertex of the surface of the sixth lens in the vicinity of the object side optical axis, and an on-axis distance SAG21 between an intersection point of a surface of the second lens in the vicinity of the object side optical axis and the optical axis to an effective radius vertex of the surface of the second lens in the vicinity of the object side optical axis satisfy: -0.5< SAG51/(SAG61-SAG21) < 0.5.

Further, an on-axis distance SAG22 between an intersection of the optical axis and a surface of the second lens in the vicinity of the image-side optical axis to an effective radius vertex of the surface of the second lens in the vicinity of the image-side optical axis, an edge thickness ET2 at a maximum effective radius of the second lens satisfies: -0.5< SAG22/ET2< 1.5.

Further, the edge thickness ET4 at the maximum effective radius of the fourth lens, the center thickness CT4 of the fourth lens, the edge thickness ET3 at the maximum effective radius of the third lens, and the center thickness CT3 of the third lens satisfy: -1.0< ET4/CT4-ET3/CT3< 1.0.

Further, the central thickness CT3 of the third lens, the air gap T34 of the third lens and the fourth lens on the optical axis, the central thickness CT4 of the fourth lens and the sum Sigma AT of the air gaps of any adjacent lenses of the first lens to the sixth lens on the optical axis satisfy 0< (CT3+ T34+ CT 4)/SigmaAT < 0.7.

Further, a sum Σ CT of center thicknesses of all lenses of the first lens to the sixth lens and a distance TD on the optical axis from a surface of the first lens in the vicinity of the object side optical axis to a surface of the sixth lens in the vicinity of the image side optical axis satisfy: 0.2< ∑ CT/TD < 1.0.

According to another aspect of the present invention, there is provided an optical imaging system including, in order from an object side to an image side: a first lens having an optical power; a second lens having an optical power; a third lens having optical power; a fourth lens having a refractive power, a surface of the fourth lens in the vicinity of an object-side optical axis being a convex surface; a fifth lens having a refractive power, a surface of the fifth lens near an image-side optical axis being a convex surface; a sixth lens having negative refractive power, a surface of the sixth lens in the vicinity of an object-side optical axis being a concave surface; the diaphragm number Fno of the optical imaging system and the half ImgH of the diagonal length of the effective pixel area on the imaging surface meet the following conditions: 7.5mm < Fno × ImgH <9 mm; the effective focal length f5 of the fifth lens and half semisum-Fov of the maximum field angle of the optical imaging system satisfy that: 4mm < f5 star (semi-Fov) <6.5 mm; the distance TTL along the optical axis between the surface of the first lens near the optical axis of the object side and the imaging surface of the optical imaging system and the air gap T56 on the optical axis between the fifth lens and the sixth lens satisfy that: 4< TTL/T56< 6.

Further, the center thickness CT3 of the third lens, the air gap T34 of the third lens and the fourth lens on the optical axis, the center thickness CT4 of the fourth lens, and the sum Sigma AT of the air gaps of any adjacent lenses of the first lens to the sixth lens on the optical axis satisfy 0< (CT3+ T34+ CT 4)/. Sigma AT < 0.7.

With the technical solution of the present invention, an optical imaging system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element. The first lens has focal power; the second lens has focal power; the third lens has focal power; the fourth lens has focal power, and the surface of the fourth lens near the object-side optical axis is a convex surface; the fifth lens has focal power, and the surface of the fifth lens near the image side optical axis is a convex surface; the sixth lens has negative focal power, and the surface of the sixth lens near the object-side optical axis is a concave surface; wherein, the f-number Fno of the optical imaging system satisfies: fno < 1.7; the effective focal length f5 of the fifth lens and half semisum-Fov of the maximum field angle of the optical imaging system satisfy that: 4mm < f5 tan (semi-Fov) <6.5 mm; the distance TTL along the optical axis between the surface of the first lens near the optical axis of the object side and the imaging surface of the optical imaging system and the air gap T56 on the optical axis between the fifth lens and the sixth lens satisfy that: 4< TTL/T56< 6.

By distributing the focal power of part of the lenses of the optical imaging system and designing the surface type of the lenses, the low-order aberration of the optical imaging system can be effectively balanced, meanwhile, the tolerance sensitivity of the optical imaging system can be reduced, the imaging quality of the optical imaging system is ensured while the miniaturization of the optical imaging system is kept, and the optical imaging system has the characteristics of a large image plane and a large aperture. By limiting Fno to a reasonable range, a large aperture characteristic of the optical imaging system can be ensured. And f5 tan (semi-Fov) is controlled within a reasonable range, so that the maximum field angle of the optical imaging system can be controlled within a reasonable range to ensure the characteristic of a large image plane of the optical imaging system. And by limiting TTL/T56 to a reasonable range, the total length of the optical imaging system can be ensured to be in a reasonable range, so that the miniaturization of the optical imaging system is ensured.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic configuration diagram showing an optical imaging system according to a first example of the present invention;

fig. 2 to 5 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging system in fig. 1;

fig. 6 is a schematic configuration diagram showing an optical imaging system of a second example of the present invention;

fig. 7 to 10 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging system in fig. 6;

fig. 11 is a schematic configuration diagram showing an optical imaging system of example three of the present invention;

fig. 12 to 15 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging system in fig. 11;

fig. 16 is a schematic configuration diagram showing an optical imaging system of example four of the present invention;

fig. 17 to 20 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a chromatic aberration of magnification curve, respectively, of the optical imaging system in fig. 16;

fig. 21 is a schematic configuration diagram showing an optical imaging system of example five of the present invention;

fig. 22 to 25 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging system in fig. 21;

fig. 26 is a schematic structural view showing an optical imaging system of example six of the present invention;

fig. 27 to 30 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a chromatic aberration of magnification curve of the optical imaging system in fig. 26, respectively;

fig. 31 is a schematic configuration diagram showing an optical imaging system of example seven of the present invention;

fig. 32 to 35 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a chromatic aberration of magnification curve, respectively, of the optical imaging system in fig. 31;

fig. 36 is a schematic structural view showing an optical imaging system of example eight of the present invention;

fig. 37 to 40 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a chromatic aberration of magnification curve, respectively, of the optical imaging system in fig. 36.

Wherein the figures include the following reference numerals:

e1, first lens; s1, a surface of the first lens in the vicinity of the object-side optical axis; s2, a surface of the first lens near the image side optical axis; e2, second lens; s3, a surface of the second lens in the vicinity of the object-side optical axis; s4, a surface of the second lens near the image-side optical axis; e3, third lens; s5, a surface of the third lens in the vicinity of the object-side optical axis; s6, a surface of the third lens element near the image-side optical axis; e4, fourth lens; s7, a surface of the fourth lens near the object-side optical axis; s8, a surface of the fourth lens element near the image-side optical axis; e5, fifth lens; s9, a surface of the fifth lens in the vicinity of the object-side optical axis; s10, a surface of the fifth lens element near the image-side optical axis; e6, sixth lens; s11, a surface of the sixth lens in the vicinity of the object-side optical axis; s12, a surface of the sixth lens element near the image-side optical axis; e7, a filter plate; s13, the surface of the filter sheet near the object side optical axis; s14, the surface of the filter sheet near the image side optical axis; and S15, imaging surface.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

It is noted that, unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

In the present invention, unless specified to the contrary, use of the terms of orientation such as "upper, lower, top, bottom" or the like, generally refer to the orientation as shown in the drawings, or to the component itself in a vertical, perpendicular, or gravitational orientation; likewise, for ease of understanding and description, "inner and outer" refer to inner and outer relative to the profile of the components themselves, but the above directional terms are not intended to limit the invention.

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

In the drawings, the thickness, size, and shape of the lens have been slightly exaggerated for convenience of explanation. In particular, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and not drawn to scale.

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position 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 concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The determination of the surface shape in the paraxial region can be performed by determining whether or not the surface shape is concave or convex, based on the R value (R denotes the radius of curvature of the paraxial region, and usually denotes the R value in a lens database (lens data) in optical software) in accordance with the determination method of a person ordinarily skilled in the art. Regarding a surface in the vicinity of the object-side optical axis, a convex surface is determined when the R value is positive, and a concave surface is determined when the R value is negative; a surface in the vicinity of the image-side optical axis is determined to be a concave surface when the R value is positive, and is determined to be a convex surface when the R value is negative.

The invention provides an optical imaging system, which aims to solve the problem of poor imaging quality of the optical imaging system in the prior art.

Example one

As illustrated in fig. 1 to 40, the optical imaging system includes, in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens has focal power; the second lens has focal power; the third lens has focal power; the fourth lens has focal power, and the surface of the fourth lens near the object-side optical axis is a convex surface; the fifth lens has focal power, and the surface of the fifth lens near the image side optical axis is a convex surface; the sixth lens has negative focal power, and the surface of the sixth lens near the object-side optical axis is a concave surface; wherein, the f-number Fno of the optical imaging system satisfies: fno < 1.7; the effective focal length f5 of the fifth lens and half semisum-Fov of the maximum field angle of the optical imaging system satisfy that: 4mm < f5 tan (semi-Fov) <6.5 mm; the distance TTL along the optical axis between the surface of the first lens near the optical axis of the object side and the imaging surface of the optical imaging system and the air gap T56 on the optical axis between the fifth lens and the sixth lens satisfy that: 4< TTL/T56< 6.

Preferably, the f-number Fno of the optical imaging system satisfies: 1.5< Fno < 1.7; the effective focal length f5 of the fifth lens and half semisum-Fov of the maximum field angle of the optical imaging system satisfy that: 4.2mm < f5 tan (semi-Fov) <6.0 mm; the distance TTL along the optical axis between the surface of the first lens near the optical axis of the object side and the imaging surface of the optical imaging system and the air gap T56 on the optical axis between the fifth lens and the sixth lens satisfy that: 4.1< TTL/T56< 5.9.

In the present embodiment, the air gap T56 on the optical axis between the fifth lens and the sixth lens and the effective focal length f of the optical imaging system satisfy: 3< f/T56< 5. By limiting f/T56 within a reasonable range, the focal length of the optical imaging system can be ensured within a reasonable range, and the imaging quality of the optical imaging system is guaranteed. Preferably 3.2< f/T56< 4.8.

In the present embodiment, a distance TTL along the optical axis from the surface of the first lens in the vicinity of the object side optical axis to the imaging plane of the optical imaging system, a sum Σ CT of center thicknesses of all lenses of the first lens to the sixth lens, and a half ImgH of a diagonal length of the effective pixel region on the imaging plane satisfy: 0.5< (TTL-sigma CT)/ImgH < 1.5. By limiting the (TTL-Sigma CT)/ImgH within a reasonable range, the CRA design of the optical imaging system and the balance of aberration are better realized. Preferably, 0.6< (TTL-sigma CT)/ImgH < 1.0.

In the present embodiment, the optical imaging system satisfies the relationship between the f-number Fno and the half length ImgH of the diagonal line of the effective pixel area on the imaging plane: 7.5mm < Fno ImgH <9 mm. By limiting Fno ImgH within a reasonable range, the optical imaging system ensures a large imaging surface while realizing a large aperture. Preferably, 7.7mm < Fno ImgH <8.5 mm.

In the present embodiment, the effective focal length f5 of the fifth lens and the effective focal length f of the optical imaging system satisfy: 0.4< f5/f < 1.5. By limiting f5/f within a reasonable range, the distribution of the optical power of the optical imaging system can be better realized, and the axial aberration of the optical imaging system can be better corrected. Preferably 0.6< f5/f < 1.3.

In the present embodiment, a distance TTL along the optical axis from the surface of the first lens in the vicinity of the object side optical axis to the imaging surface of the optical imaging system, an effective focal length f of the optical imaging system, and an effective focal length f6 of the sixth lens satisfy: 3.0< TTL/(f + f6) < 6.0. The TTL/(f + f6) is limited within a reasonable range, so that the wide-angle performance of the optical imaging system is ensured, and the miniaturization of the system is ensured. Preferably, 3.1< TTL/(f + f6) < 5.8.

In this embodiment, a combined focal length f123 of the first lens, the second lens, and the third lens and a combined focal length f2345 of the second lens, the third lens, the fourth lens, and the fifth lens satisfy: 1.0< f123/f2345< 2.5. Through the design of the first five lenses, the optical imaging system is favorably realized to have the characteristic of a large aperture, and the aberration of the optical imaging system is favorably corrected. Preferably, 1.2< f123/f2345< 2.2.

In the present embodiment, a radius of curvature R10 of a surface of the fifth lens in the vicinity of the image-side optical axis and a radius of curvature R11 of a surface of the sixth lens in the vicinity of the object-side optical axis satisfy: -0.5< (R10-R11)/(R10+ R11) < 0.5. By limiting (R10-R11)/(R10+ R11) within a reasonable range, curvature of field and astigmatism of the optical imaging system can be better corrected, and higher imaging quality can be obtained. Preferably, -0.3< (R10-R11)/(R10+ R11) < 0.4.

In the present embodiment, the central thickness CT1 of the first lens, the air gap T12 of the first lens and the second lens on the optical axis, the central thickness CT2 of the second lens, the air gap T23 of the second lens and the third lens on the optical axis, and the central thickness CT3 of the third lens satisfy: 6.0< (CT1+ T12+ CT2+ T23+ CT3)/CT2< 8.5. By limiting (CT1+ T12+ CT2+ T23+ CT3)/CT2 within a reasonable range, the characteristic of a large aperture can be better realized, and the axial aberration of the optical imaging system can be favorably corrected. Preferably, 6.5< (CT1+ T12+ CT2+ T23+ CT3)/CT2< 8.2.

In this embodiment, the on-axis distance SAG51 between the intersection point of the surface of the fifth lens near the object-side optical axis and the optical axis to the effective radius vertex of the surface of the fifth lens near the object-side optical axis, the on-axis distance SAG61 between the intersection point of the surface of the sixth lens near the object-side optical axis and the optical axis to the effective radius vertex of the surface of the sixth lens near the object-side optical axis, and the on-axis distance SAG21 between the intersection point of the surface of the second lens near the object-side optical axis and the optical axis to the effective radius vertex of the surface of the second lens near the object-side optical axis satisfy: -0.5< SAG51/(SAG61-SAG21) < 0.5. By limiting SAG51/(SAG61-SAG21) to a reasonable range, the shapes of the fifth lens and the sixth lens can be limited to better correct off-axis aberrations of the optical imaging system, such as correction of field curvature and correction of object astigmatism. Preferably, -0.3< SAG51/(SAG61-SAG21) < 0.45.

In the present embodiment, the on-axis distance SAG22 between the intersection point of the optical axis and the surface of the second lens in the vicinity of the image side optical axis to the effective radius vertex of the surface of the second lens in the vicinity of the image side optical axis, the edge thickness ET2 at the maximum effective radius of the second lens satisfies: -0.5< SAG22/ET2< 1.5. By limiting SAG22/ET2 within a reasonable range, astigmatism and field curvature of the optical imaging system can be effectively reduced, and better imaging quality can be obtained. Preferably, -0.3< SAG22/ET2< 1.4.

In the present embodiment, the edge thickness ET4 at the maximum effective radius of the fourth lens, the center thickness CT4 of the fourth lens, the edge thickness ET3 at the maximum effective radius of the third lens, and the center thickness CT3 of the third lens satisfy: -1.0< ET4/CT4-ET3/CT3< 1.0. Such an arrangement can be advantageous for correcting off-axis aberrations of the optical imaging system, such as field curvature, astigmatism, distortion, homeotropic aberrations, and the like. Preferably, -0.9< ET4/CT4-ET3/CT3< 0.8.

In the present embodiment, the sum Σ AT of the center thickness CT3 of the third lens, the air gap T34 on the optical axis of the third lens and the fourth lens, the center thickness CT4 of the fourth lens, and the air gap on the optical axis of any adjacent lens of the first lens to the sixth lens satisfies 0< (CT3+ T34+ CT4)/∑ AT < 0.7. By controlling (CT3+ T34+ CT 4)/. Sigma AT in a reasonable range, the spherical aberration and the axial chromatic aberration can be well balanced, and the characteristic of a large aperture can be better realized. Preferably, 0.1< (CT3+ T34+ CT 4)/. Sigma AT < 0.6.

In the present embodiment, a sum Σ CT of center thicknesses of all lenses of the first lens to the sixth lens and a distance TD on the optical axis from a surface of the first lens in the vicinity of the object side optical axis to a surface of the sixth lens in the vicinity of the image side optical axis satisfy: 0.2< ∑ CT/TD < 1.0. By controlling the sigma CT/TD within a reasonable range, the balance of focal length, axial chromatic aberration and chromatic spherical aberration is facilitated, so that better imaging quality is obtained. Preferably, 0.4< ∑ CT/TD < 0.8.

Example two

As illustrated in fig. 1 to 40, the optical imaging system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element. The first lens has focal power; the second lens has focal power; the third lens has focal power; the fourth lens has focal power, and the surface of the fourth lens near the object-side optical axis is a convex surface; the fifth lens has focal power, and the surface of the fifth lens near the image side optical axis is a convex surface; the sixth lens has negative focal power, and the surface of the sixth lens near the object-side optical axis is a concave surface; the diaphragm number Fno of the optical imaging system and the half ImgH of the diagonal length of the effective pixel area on the imaging surface meet the following conditions: 7.5mm < Fno ImgH <9 mm; the effective focal length f5 of the fifth lens and half semisum-Fov of the maximum field angle of the optical imaging system satisfy that: 4mm < f5 tan (semi-Fov) <6.5 mm; the distance TTL along the optical axis between the surface of the first lens near the optical axis of the object side and the imaging surface of the optical imaging system and the air gap T56 on the optical axis between the fifth lens and the sixth lens satisfy that: 4< TTL/T56< 6.

By distributing the focal power of part of the lenses of the optical imaging system and designing the surface type of the lenses, the low-order aberration of the optical imaging system can be effectively balanced, meanwhile, the tolerance sensitivity of the optical imaging system can be reduced, the imaging quality of the optical imaging system is ensured while the miniaturization of the optical imaging system is kept, and the optical imaging system has the characteristics of a large image plane and a large aperture. By controlling f5 tan (semi-Fov) within a reasonable range, the maximum field angle of the optical imaging system can be controlled within a reasonable range to ensure the characteristics of a large image plane of the optical imaging system. And by limiting TTL/T56 to a reasonable range, the total length of the optical imaging system can be ensured to be in a reasonable range, so that the miniaturization of the optical imaging system is ensured. By limiting Fno ImgH within a reasonable range, the optical imaging system ensures a large imaging surface while realizing a large aperture.

Preferably, the optical imaging system has an f-number Fno satisfying a relationship with a half ImgH of a diagonal length of an effective pixel area on an imaging plane: 7.7mm < Fno ImgH <8.5 mm; the effective focal length f5 of the fifth lens and half semisum-Fov of the maximum field angle of the optical imaging system satisfy that: 4.2mm < f5 tan (semi-Fov) <6.0 mm; the distance TTL along the optical axis between the surface of the first lens near the optical axis of the object side and the imaging surface of the optical imaging system and the air gap T56 on the optical axis between the fifth lens and the sixth lens satisfy that: 4.1< TTL/T56< 5.9.

In the present embodiment, a distance TTL along the optical axis from the surface of the first lens in the vicinity of the object side optical axis to the imaging plane of the optical imaging system, a sum Σ CT of center thicknesses of all lenses of the first lens to the sixth lens, and a half ImgH of a diagonal length of the effective pixel region on the imaging plane satisfy: 0.5< (TTL-sigma CT)/ImgH < 1.5. By limiting the (TTL-Sigma CT)/ImgH within a reasonable range, the CRA design of the optical imaging system and the balance of aberration are facilitated to be better realized. Preferably, 0.6< (TTL-sigma CT)/ImgH < 1.0.

In this embodiment, a sum Σ CT of center thicknesses of all lenses of the first lens to the sixth lens and a distance TD on the optical axis from the surface of the first lens in the vicinity of the object side optical axis to the surface of the sixth lens in the vicinity of the image side optical axis satisfy: 0.2< ∑ CT/TD < 1.0. By controlling the sigma CT/TD within a reasonable range, the balance of focal length, axial chromatic aberration and chromatic spherical aberration is facilitated, so that better imaging quality is obtained. Preferably, 0.4< ∑ CT/TD < 0.8.

Optionally, the optical imaging system may further include a filter for correcting color deviation and/or a protective glass for protecting a photosensitive element located on the imaging surface.

The optical imaging system in the present application may employ a plurality of lenses, such as the six lenses described above. By reasonably distributing the focal power, the surface shape, the central thickness of each lens, the axial distance between each lens and the like, the imaging quality of the optical imaging system can be effectively improved, the sensitivity of the optical imaging system is reduced, and the machinability of the optical imaging system is improved, so that the optical imaging system is more favorable for production and processing and can be suitable for portable electronic equipment such as a smart phone.

In the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. The aspheric lens is characterized in that: the curvature varies continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has advantages of improving distortion aberration and improving astigmatic aberration. After the aspheric lens is adopted, the aberration generated during imaging can be eliminated as much as possible, thereby improving the imaging quality.

However, it will be appreciated by those skilled in the art that the number of lenses making up the optical imaging system can be varied to achieve the various results and advantages described in this specification without departing from the claimed subject matter. For example, although six lenses are exemplified in the embodiment, the optical imaging system is not limited to include six lenses. The optical imaging system may also include other numbers of lenses, as desired.

Examples of specific surface types and parameters applicable to the optical imaging system of the above embodiment are further described below with reference to the drawings.

It should be noted that any one of the following examples one to eight is applicable to all embodiments of the present application.

Example one

As shown in fig. 1 to 5, an optical imaging system of the first example of the present application is described. Fig. 1 shows a schematic configuration diagram of an optical imaging system of example one.

As shown in fig. 1, the optical imaging system, in order from an object side to an image side, comprises: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, filter E7, and image plane S15.

The first lens E1 has positive power, and a surface S1 of the first lens in the vicinity of the object-side optical axis is convex, and a surface S2 of the first lens in the vicinity of the image-side optical axis is concave. The second lens element E2 has negative power, and its surface S3 in the vicinity of the object-side optical axis is concave, and its surface S4 in the vicinity of the image-side optical axis is convex. The third lens E3 has positive power, and a surface S5 of the third lens in the vicinity of the object-side optical axis is concave, and a surface S6 of the third lens in the vicinity of the image-side optical axis is convex. The fourth lens element E4 has positive power, and its surface S7 in the vicinity of the object-side optical axis is convex, and its surface S8 in the vicinity of the image-side optical axis is concave. The fifth lens E5 has positive power, and a surface S9 of the fifth lens in the vicinity of the object-side optical axis is convex, and a surface S10 of the fifth lens in the vicinity of the image-side optical axis is convex. The sixth lens E6 has negative power, and a surface S11 of the sixth lens in the vicinity of the object-side optical axis is a concave surface, and a surface S12 of the sixth lens in the vicinity of the image-side optical axis is a concave surface. The filter E7 has a surface S13 of the filter in the vicinity of the object-side optical axis and a surface S14 of the filter in the vicinity of the image-side optical axis. The light from the object passes through the respective surfaces S1 to S14 in order and is finally imaged on the imaging surface S15.

In this example, the image height ImgH of the optical imaging system is 4.81 mm. The total length TTL of the optical imaging system is 6.65 mm.

Table 1 shows a basic structural parameter table of the optical imaging system of example one, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm).

TABLE 1

In example one, a surface of any one of the first lens element E1 to the sixth lens element E6 near the object-side optical axis and a surface of the lens element near the image-side optical axis are aspheric, and the surface type of each aspheric lens element can be defined by, but is not limited to, the following aspheric formula:

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is a conic coefficient; ai is the correction coefficient of the i-th order of the aspherical surface. Table 2 below gives the high-order coefficient A4, A6, A8, A10, A12, A14, A16 that can be used for each of the aspherical mirrors S1-S12 in example one.

TABLE 2

Fig. 2 shows an on-axis chromatic aberration curve of the optical imaging system of example one, which represents the deviation of the convergent focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 3 shows astigmatism curves of the optical imaging system of example one, which represent meridional field curvature and sagittal field curvature. Fig. 4 shows distortion curves of the optical imaging system of example one, which represent distortion magnitude values corresponding to different angles of view. Fig. 5 shows a chromatic aberration of magnification curve of the optical imaging system of the first example, which represents the deviation of different image heights on the imaging plane after the light passes through the optical imaging system.

As can be seen from fig. 2 to 5, the optical imaging system of example one can achieve good imaging quality.

Example two

As shown in fig. 6 to 10, an optical imaging system of example two of the present application is described. Fig. 6 shows a schematic configuration diagram of an optical imaging system of example two.

As shown in fig. 6, the optical imaging system, in order from an object side to an image side, comprises: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, filter E7, and image plane S15.

The first lens E1 has positive power, and a surface S1 of the first lens in the vicinity of the object-side optical axis is convex, and a surface S2 of the first lens in the vicinity of the image-side optical axis is concave. The second lens element E2 has negative power, and its surface S3 in the vicinity of the object-side optical axis is convex, and its surface S4 in the vicinity of the image-side optical axis is concave. The third lens element E3 has negative power, and its surface S5 in the vicinity of the object-side optical axis is convex, and its surface S6 in the vicinity of the image-side optical axis is concave. The fourth lens element E4 has positive power, and its surface S7 in the vicinity of the object-side optical axis is convex, and its surface S8 in the vicinity of the image-side optical axis is convex. The fifth lens E5 has positive power, and a surface S9 of the fifth lens in the vicinity of the object-side optical axis is convex, and a surface S10 of the fifth lens in the vicinity of the image-side optical axis is convex. The sixth lens E6 has negative power, and a surface S11 of the sixth lens in the vicinity of the object-side optical axis is a concave surface, and a surface S12 of the sixth lens in the vicinity of the image-side optical axis is a concave surface. Filter E7 has surface S13 of the filter in the vicinity of the object-side optical axis and surface S14 of the filter in the vicinity of the image-side optical axis. The light from the object passes through the respective surfaces S1 to S14 in order and is finally imaged on the imaging surface S15.

In this example, the image height ImgH of the optical imaging system is 4.88 mm. The total length TTL of the optical imaging system is 6.65 mm.

Table 3 shows a basic structural parameter table of the optical imaging system of example two, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm).

TABLE 3

Table 4 shows the high-order term coefficients that can be used for each aspherical mirror in example two, wherein each aspherical mirror type can be defined by formula (1) given in example one above.

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

1.49E-03

1.65E-04

3.10E-04

5.14E-05

2.22E-05

-1.88E-05

2.59E-06

S2

-3.44E-03

9.10E-03

-1.49E-02

1.26E-02

-5.74E-03

1.28E-03

-1.06E-04

S3

1.78E-02

-6.18E-02

7.46E-02

-5.82E-02

2.92E-02

-8.38E-03

9.97E-04

S4

1.96E-02

-7.70E-02

7.87E-02

-4.43E-02

1.78E-02

-4.32E-03

4.14E-04

S5

-4.23E-02

-4.03E-03

-1.99E-02

3.19E-02

-1.78E-02

5.01E-03

-6.02E-04

S6

-5.33E-02

4.72E-02

-6.41E-02

4.96E-02

-2.11E-02

4.66E-03

-4.02E-04

S7

-4.63E-02

8.50E-03

1.27E-02

-1.70E-02

9.12E-03

-2.34E-03

2.26E-04

S8

-6.20E-02

1.37E-02

-3.22E-03

-4.34E-06

2.26E-04

-2.06E-05

-9.22E-07

S9

-1.06E-02

3.36E-04

-5.14E-04

1.55E-04

-1.93E-05

1.18E-06

-2.94E-08

S10

2.17E-02

-2.96E-03

-3.72E-04

2.04E-04

-3.06E-05

2.00E-06

-4.57E-08

S11

5.08E-03

-4.16E-03

5.00E-04

7.14E-04

-4.78E-04

1.75E-04

-4.41E-05

S12

-1.63E-02

1.67E-03

-1.13E-04

7.57E-06

-7.19E-07

4.04E-08

-7.38E-10

Flour mark

A18

A20

A22

A24

A26

A28

A30

S1

0.00E+00

S2

-2.19E-06

0.00E+00

S3

0.00E+00

S4

0.00E+00

S5

0.00E+00

S6

-5.20E-06

0.00E+00

S7

2.07E-06

0.00E+00

S8

-7.34E-08

0.00E+00

S9

0.00E+00

S10

-2.03E-10

-4.89E-12

0.00E+00

S11

7.89E-06

-1.01E-06

9.25E-08

-5.85E-09

2.44E-10

-6.02E-12

6.65E-14

S12

-2.28E-12

-4.74E-14

0.00E+00

TABLE 4

Fig. 7 shows on-axis chromatic aberration curves of the optical imaging system of example two, which represent the deviation of the convergent focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 8 shows astigmatism curves of the optical imaging system of example two, which represent meridional field curvature and sagittal field curvature. Fig. 9 shows distortion curves of the optical imaging system of example two, which indicate distortion magnitude values corresponding to different angles of view. Fig. 10 shows a chromatic aberration of magnification curve of the optical imaging system of example two, which represents the deviation of different image heights on the imaging plane after the light passes through the optical imaging system.

As can be seen from fig. 7 to 10, the optical imaging system of example two can achieve good imaging quality.

Example III

As shown in fig. 11 to 15, an optical imaging system of example three of the present application is described. Fig. 11 shows a schematic configuration diagram of an optical imaging system of example three.

As shown in fig. 11, the optical imaging system, in order from an object side to an image side, comprises: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, filter E7, and image plane S15.

The first lens E1 has positive power, and a surface S1 of the first lens in the vicinity of the object-side optical axis is convex, and a surface S2 of the first lens in the vicinity of the image-side optical axis is concave. The second lens element E2 has negative power, and its surface S3 in the vicinity of the object-side optical axis is concave, and its surface S4 in the vicinity of the image-side optical axis is concave. The third lens E3 has positive power, and a surface S5 of the third lens in the vicinity of the object-side optical axis is concave, and a surface S6 of the third lens in the vicinity of the image-side optical axis is convex. The fourth lens element E4 has positive power, and its surface S7 in the vicinity of the object-side optical axis is convex, and its surface S8 in the vicinity of the image-side optical axis is concave. The fifth lens E5 has positive power, and a surface S9 of the fifth lens in the vicinity of the object-side optical axis is convex, and a surface S10 of the fifth lens in the vicinity of the image-side optical axis is convex. The sixth lens E6 has negative power, and a surface S11 of the sixth lens in the vicinity of the object-side optical axis is a concave surface, and a surface S12 of the sixth lens in the vicinity of the image-side optical axis is a concave surface. The filter E7 has a surface S13 of the filter in the vicinity of the object-side optical axis and a surface S14 of the filter in the vicinity of the image-side optical axis. The light from the object passes through the respective surfaces S1 to S14 in order and is finally imaged on the imaging surface S15.

In this example, the image height ImgH of the optical imaging system is 4.80 mm. The total length TTL of the optical imaging system is 6.65 mm.

Table 5 shows a basic structural parameter table of the optical imaging system of example three, in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 5

Table 6 shows the high-order term coefficients that can be used for each aspherical mirror surface in example three, wherein each aspherical mirror surface type can be defined by formula (1) given in example one above.

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

-8.01E-04

-7.83E-03

9.12E-03

-6.69E-03

2.65E-03

-5.21E-04

2.20E-05

S2

-1.07E-02

1.37E-02

-1.72E-02

1.46E-02

-6.99E-03

1.69E-03

-1.61E-04

S3

-2.34E-02

2.21E-02

-3.26E-03

-3.54E-03

1.91E-03

-4.64E-04

4.51E-05

S4

-6.80E-03

-2.99E-02

4.19E-02

-2.55E-02

8.36E-03

-1.50E-03

1.18E-04

S5

8.65E-02

-1.47E-01

1.27E-01

-5.97E-02

1.59E-02

-2.15E-03

9.95E-05

S6

1.12E-02

-5.08E-02

6.17E-02

-3.42E-02

9.54E-03

-1.22E-03

4.57E-05

S7

-8.24E-02

1.82E-02

-1.22E-02

1.40E-02

-8.85E-03

2.55E-03

-2.62E-04

S8

-4.17E-02

4.82E-03

-1.34E-02

1.56E-02

-7.96E-03

1.92E-03

-1.65E-04

S9

6.49E-03

-4.05E-03

1.21E-03

-2.15E-04

3.27E-06

3.13E-06

-2.27E-07

S10

1.64E-02

-4.74E-03

1.54E-03

-2.69E-04

2.17E-05

-6.18E-07

-5.66E-10

S11

-5.25E-02

8.65E-03

-2.84E-03

2.76E-03

-1.91E-03

9.09E-04

-3.04E-04

S12

-5.03E-02

9.68E-03

-1.56E-03

1.83E-04

-1.35E-05

5.07E-07

-5.95E-09

Flour mark

A18

A20

A22

A24

A26

A28

A30

S1

5.26E-06

0.00E+00

S2

0.00E+00

S3

0.00E+00

S4

0.00E+00

S5

0.00E+00

S6

0.00E+00

S7

-1.37E-06

0.00E+00

S8

-1.57E-06

0.00E+00

S9

0.00E+00

S10

-2.93E-10

0.00E+00

S11

7.29E-05

-1.25E-05

1.53E-06

-1.30E-07

7.29E-09

-2.42E-10

3.63E-12

S12

-7.35E-11

7.82E-13

-3.98E-14

0.00E+00

TABLE 6

Fig. 12 shows an on-axis chromatic aberration curve of the optical imaging system of example three, which represents the convergent focus deviation of light rays of different wavelengths after passing through the optical imaging system. Fig. 13 shows astigmatism curves of the optical imaging system of example three, which represent meridional field curvature and sagittal field curvature. Fig. 14 shows distortion curves of the optical imaging system of example three, which represent distortion magnitude values corresponding to different angles of view. Fig. 15 shows a chromatic aberration of magnification curve of the optical imaging system of example three, which represents the deviation of different image heights on the imaging plane after the light passes through the optical imaging system.

As can be seen from fig. 12 to 15, the optical imaging system of example three can achieve good imaging quality.

Example four

As shown in fig. 16 to 20, an optical imaging system of example four of the present application is described. Fig. 16 shows a schematic configuration diagram of an optical imaging system of example four.

As shown in fig. 16, the optical imaging system, in order from an object side to an image side, comprises: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, filter E7, and image plane S15.

The first lens E1 has positive optical power, and a surface S1 of the first lens in the vicinity of the object-side optical axis is a convex surface, and a surface S2 of the first lens in the vicinity of the image-side optical axis is a concave surface. The second lens element E2 has positive refractive power, and its surface S3 in the vicinity of the object-side optical axis is convex, and its surface S4 in the vicinity of the image-side optical axis is concave. The third lens element E3 has negative power, and its surface S5 in the vicinity of the object-side optical axis is concave, and its surface S6 in the vicinity of the image-side optical axis is convex. The fourth lens element E4 has negative power, and its surface S7 in the vicinity of the object-side optical axis is convex, and its surface S8 in the vicinity of the image-side optical axis is concave. The fifth lens E5 has positive power, and a surface S9 of the fifth lens in the vicinity of the object-side optical axis is concave, and a surface S10 of the fifth lens in the vicinity of the image-side optical axis is convex. The sixth lens E6 has negative power, and a surface S11 of the sixth lens in the vicinity of the object-side optical axis is a concave surface, and a surface S12 of the sixth lens in the vicinity of the image-side optical axis is a concave surface. The filter E7 has a surface S13 of the filter in the vicinity of the object-side optical axis and a surface S14 of the filter in the vicinity of the image-side optical axis. The light from the object passes through the respective surfaces S1 to S14 in order and is finally imaged on the imaging surface S15.

In this example, the image height ImgH of the optical imaging system is 4.92 mm. The total length TTL of the optical imaging system is 6.65 mm.

Table 7 shows a basic structural parameter table of the optical imaging system of example four, in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 7

Table 8 shows the high-order term coefficients that can be used for each aspherical mirror surface in example four, wherein each aspherical mirror surface type can be defined by formula (1) given in example one above.

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

2.76E-03

-4.11E-03

6.44E-03

-4.20E-03

1.40E-03

-2.22E-04

1.40E-05

S2

6.30E-03

-2.56E-03

7.06E-04

-9.02E-05

0.00E+00

S3

-6.24E-02

-1.57E-02

2.90E-02

-1.38E-02

3.31E-03

-8.33E-05

-1.04E-04

S4

-5.16E-03

-2.28E-02

1.93E-03

2.89E-02

-2.55E-02

8.94E-03

-7.13E-04

S5

4.01E-02

-6.85E-02

5.90E-02

-2.91E-02

5.62E-03

6.63E-04

-3.02E-04

S6

2.42E-02

-3.17E-02

2.56E-02

-5.79E-03

-2.73E-03

1.66E-03

-2.32E-04

S7

-4.60E-02

1.84E-02

-8.41E-04

-1.62E-03

5.87E-04

-8.67E-05

4.88E-06

S8

-3.82E-02

3.53E-03

1.32E-03

-1.50E-03

4.57E-04

-5.37E-05

1.86E-06

S9

-6.39E-03

-7.24E-03

4.10E-03

-1.42E-03

2.48E-04

-1.87E-05

3.64E-07

S10

4.52E-03

-1.88E-03

5.69E-05

2.61E-04

-5.88E-05

3.64E-06

4.22E-08

S11

-4.11E-03

-3.09E-03

1.43E-03

1.22E-04

-2.56E-04

1.13E-04

-3.13E-05

S12

-1.51E-02

8.43E-04

1.04E-04

-2.36E-05

1.62E-06

-4.41E-08

3.45E-10

Flour mark

A18

A20

A22

A24

A26

A28

A30

S1

0.00E+00

S2

0.00E+00

S3

0.00E+00

S4

-1.78E-04

0.00E+00

S5

0.00E+00

S6

-2.96E-06

0.00E+00

S7

0.00E+00

S8

3.18E-08

0.00E+00

S9

8.43E-09

0.00E+00

S10

-1.01E-08

4.22E-10

0.00E+00

S11

6.11E-06

-8.57E-07

8.53E-08

-5.89E-09

2.68E-10

-7.21E-12

8.70E-14

S12

-6.01E-13

7.51E-14

0.00E+00

TABLE 8

Fig. 17 shows an on-axis chromatic aberration curve of the optical imaging system of example four, which represents the convergent focus deviation of light rays of different wavelengths after passing through the optical imaging system. Fig. 18 shows astigmatism curves of the optical imaging system of example four, which represent meridional field curvature and sagittal field curvature. Fig. 19 shows distortion curves of the optical imaging system of example four, which represent distortion magnitude values corresponding to different angles of view. Fig. 20 shows a chromatic aberration of magnification curve of the optical imaging system of example four, which represents the deviation of different image heights on the imaging plane after the light passes through the optical imaging system.

As can be seen from fig. 17 to 20, the optical imaging system according to example four can achieve good imaging quality.

Example five

As shown in fig. 21 to 25, an optical imaging system of example five of the present application is described. Fig. 21 shows a schematic configuration diagram of an optical imaging system of example five.

As shown in fig. 21, the optical imaging system includes, in order from an object side to an image side: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, filter E7, and image plane S15.

The first lens E1 has positive power, and a surface S1 of the first lens in the vicinity of the object-side optical axis is convex, and a surface S2 of the first lens in the vicinity of the image-side optical axis is concave. The second lens element E2 has negative power, and its surface S3 in the vicinity of the object-side optical axis is convex, and its surface S4 in the vicinity of the image-side optical axis is concave. The third lens E3 has positive power, and a surface S5 of the third lens in the vicinity of the object-side optical axis is convex, and a surface S6 of the third lens in the vicinity of the image-side optical axis is concave. The fourth lens element E4 has positive power, and its surface S7 in the vicinity of the object-side optical axis is convex, and its surface S8 in the vicinity of the image-side optical axis is convex. The fifth lens E5 has positive power, and a surface S9 of the fifth lens in the vicinity of the object-side optical axis is concave, and a surface S10 of the fifth lens in the vicinity of the image-side optical axis is convex. The sixth lens element E6 has negative power, and its surface S11 in the vicinity of the object-side optical axis is concave, and its surface S12 in the vicinity of the image-side optical axis is convex. The filter E7 has a surface S13 of the filter in the vicinity of the object-side optical axis and a surface S14 of the filter in the vicinity of the image-side optical axis. The light from the object passes through the respective surfaces S1 to S14 in order and is finally imaged on the imaging surface S15.

In this example, the image height ImgH of the optical imaging system is 4.84 mm. The total length TTL of the optical imaging system is 6.65 mm.

Table 9 shows a basic structural parameter table of the optical imaging system of example five, in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 9

Table 10 shows the high-order term coefficients that can be used for each aspherical mirror surface in example five, wherein each aspherical mirror surface type can be defined by formula (1) given in example one above.

Watch 10

Fig. 22 shows on-axis chromatic aberration curves of the optical imaging system of example five, which represent the convergent focus deviation of light rays of different wavelengths after passing through the optical imaging system. Fig. 23 shows astigmatism curves of the optical imaging system of example five, which represent meridional field curvature and sagittal field curvature. Fig. 24 shows distortion curves of the optical imaging system of example five, which represent distortion magnitude values corresponding to different angles of view. Fig. 25 shows a chromatic aberration of magnification curve of the optical imaging system of example five, which represents the deviation of different image heights on the imaging plane after the light passes through the optical imaging system.

As can be seen from fig. 22 to 25, the optical imaging system according to example five can achieve good imaging quality.

Example six

As shown in fig. 26 to 30, an optical imaging system of example six of the present application is described. Fig. 26 shows a schematic configuration diagram of an optical imaging system of example six.

As shown in fig. 26, the optical imaging system, in order from an object side to an image side, comprises: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, filter E7, and image plane S15.

The first lens E1 has positive power, and a surface S1 of the first lens in the vicinity of the object-side optical axis is convex, and a surface S2 of the first lens in the vicinity of the image-side optical axis is concave. The second lens element E2 has negative power, and its surface S3 in the vicinity of the object-side optical axis is convex, and its surface S4 in the vicinity of the image-side optical axis is concave. The third lens E3 has negative power, and a surface S5 of the third lens in the vicinity of the object-side optical axis is a convex surface, and a surface S6 of the third lens in the vicinity of the image-side optical axis is a concave surface. The fourth lens element E4 has positive power, and its surface S7 in the vicinity of the object-side optical axis is convex, and its surface S8 in the vicinity of the image-side optical axis is convex. The fifth lens E5 has positive power, and a surface S9 of the fifth lens in the vicinity of the object-side optical axis is convex, and a surface S10 of the fifth lens in the vicinity of the image-side optical axis is convex. The sixth lens E6 has negative power, and a surface S11 of the sixth lens in the vicinity of the object-side optical axis is a concave surface, and a surface S12 of the sixth lens in the vicinity of the image-side optical axis is a concave surface. The filter E7 has a surface S13 of the filter in the vicinity of the object-side optical axis and a surface S14 of the filter in the vicinity of the image-side optical axis. The light from the object passes through the respective surfaces S1 to S14 in order and is finally imaged on the imaging surface S15.

In this example, the image height ImgH of the optical imaging system is 4.85 mm. The total length TTL of the optical imaging system is 6.60 mm.

Table 11 shows a basic structural parameter table of the optical imaging system of example six, in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 11

Table 12 shows the high-order term coefficients that can be used for each of the aspherical mirror surfaces in example six, wherein each aspherical mirror surface type can be defined by formula (1) given in example one above.

TABLE 12

Fig. 27 shows an on-axis chromatic aberration curve of the optical imaging system of example six, which represents the convergent focus deviation of light rays of different wavelengths after passing through the optical imaging system. Fig. 28 shows astigmatism curves of the optical imaging system of example six, which represent meridional field curvature and sagittal field curvature. Fig. 29 shows distortion curves of the optical imaging system of example six, which represent distortion magnitude values corresponding to different angles of view. Fig. 30 shows a chromatic aberration of magnification curve of the optical imaging system of example six, which represents the deviation of different image heights on the imaging plane after the light passes through the optical imaging system.

As can be seen from fig. 27 to 30, the optical imaging system according to example six can achieve good imaging quality.

Example seven

As shown in fig. 31 to 35, an optical imaging system of example seven of the present application is described. Fig. 31 shows a schematic configuration diagram of an optical imaging system of example seven.

As shown in fig. 31, the optical imaging system, in order from an object side to an image side, comprises: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, filter E7, and image plane S15.

The first lens E1 has positive optical power, and a surface S1 of the first lens in the vicinity of the object-side optical axis is a convex surface, and a surface S2 of the first lens in the vicinity of the image-side optical axis is a concave surface. The second lens element E2 has positive refractive power, and its surface S3 in the vicinity of the object-side optical axis is convex, and its surface S4 in the vicinity of the image-side optical axis is concave. The third lens element E3 has negative power, and its surface S5 in the vicinity of the object-side optical axis is concave, and its surface S6 in the vicinity of the image-side optical axis is convex. The fourth lens element E4 has negative power, and its surface S7 in the vicinity of the object-side optical axis is convex, and its surface S8 in the vicinity of the image-side optical axis is concave. The fifth lens E5 has positive power, and a surface S9 of the fifth lens in the vicinity of the object-side optical axis is concave, and a surface S10 of the fifth lens in the vicinity of the image-side optical axis is convex. The sixth lens E6 has negative power, and a surface S11 of the sixth lens in the vicinity of the object-side optical axis is a concave surface, and a surface S12 of the sixth lens in the vicinity of the image-side optical axis is a concave surface. The filter E7 has a surface S13 of the filter in the vicinity of the object-side optical axis and a surface S14 of the filter in the vicinity of the image-side optical axis. Light from the object sequentially passes through the respective surfaces S1 to S14 and is finally imaged on the imaging surface S15.

In this example, the image height ImgH of the optical imaging system is 4.92 mm. The total length TTL of the optical imaging system is 6.59 mm.

Table 13 shows a basic structural parameter table of the optical imaging system of example seven, in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm).

Watch 13

Table 14 shows the high-order term coefficients that can be used for each of the aspherical mirror surfaces in example seven, wherein each of the aspherical mirror surface types can be defined by formula (1) given in example one above.

TABLE 14

Fig. 32 shows an on-axis chromatic aberration curve of the optical imaging system of example seven, which represents the convergent focus deviation of light rays of different wavelengths after passing through the optical imaging system. Fig. 33 shows astigmatism curves of the optical imaging system of example seven, which represent meridional field curvature and sagittal field curvature. Fig. 34 shows distortion curves of the optical imaging system of example seven, which represent distortion magnitude values corresponding to different angles of view. Fig. 35 shows a chromatic aberration of magnification curve of the optical imaging system of example seven, which represents the deviation of different image heights on the imaging plane after the light passes through the optical imaging system.

As can be seen from fig. 32 to 35, the optical imaging system according to example seven can achieve good imaging quality.

Example eight

As shown in fig. 36 to 40, an optical imaging system of example eight of the present application is described. Fig. 36 shows a schematic configuration diagram of an optical imaging system of example eight.

As shown in fig. 36, the optical imaging system, in order from an object side to an image side, comprises: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, filter E7, and image plane S15.

In this example, the image height ImgH of the optical imaging system is 4.85 mm. The total length TTL of the optical imaging system was 6.67 mm.

Table 15 shows a basic structural parameter table of the optical imaging system of example eight, in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm).

Watch 15

Table 16 shows the high-order term coefficients that can be used for each aspherical mirror in example eight, wherein each aspherical mirror type can be defined by formula (1) given in example one above.

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

3.48E-04

-1.09E-03

5.22E-04

2.87E-05

-6.00E-06

1.92E-06

0.00E+00

S2

-1.13E-03

-7.11E-03

3.29E-03

-5.94E-04

-1.28E-05

0.00E+00

S3

1.85E-02

-3.19E-02

1.49E-02

-2.75E-03

1.60E-06

0.00E+00

S4

2.98E-03

-1.36E-02

1.11E-02

-2.27E-03

-6.98E-06

0.00E+00

S5

-6.43E-02

1.84E-02

-2.13E-03

-2.29E-05

0.00E+00

S6

-3.63E-02

2.80E-03

1.49E-03

-2.42E-04

-4.75E-06

-7.59E-07

0.00E+00

S7

-9.09E-03

-3.62E-03

1.36E-03

-1.38E-04

-4.17E-07

0.00E+00

S8

-2.24E-02

2.82E-03

-1.25E-03

2.00E-04

3.36E-06

5.46E-07

0.00E+00

S9

-2.16E-02

1.08E-03

4.97E-04

-6.07E-05

-1.07E-06

-1.91E-08

-1.99E-09

S10

2.39E-03

-5.56E-04

8.31E-04

-9.59E-05

9.23E-06

-1.40E-06

6.60E-08

S11

2.43E-02

-4.83E-03

4.63E-04

-1.13E-05

-5.50E-07

1.12E-07

-2.64E-08

S12

4.60E-03

-1.68E-03

1.42E-04

-5.33E-06

4.66E-08

5.88E-10

3.13E-11

Flour mark

A18

A20

A22

A24

A26

A28

A30

S1

0.00E+00

S2

0.00E+00

S3

0.00E+00

S4

0.00E+00

S5

0.00E+00

S6

0.00E+00

S7

0.00E+00

S8

0.00E+00

S9

0.00E+00

S10

0.00E+00

S11

3.64E-09

-3.26E-10

1.67E-11

-3.93E-13

0.00E+00

S12

1.62E-13

0.00E+00

TABLE 16

Fig. 37 shows an on-axis chromatic aberration curve of the optical imaging system of example eight, which represents the convergent focus deviation of light rays of different wavelengths after passing through the optical imaging system. Fig. 38 shows astigmatism curves of the optical imaging system of example eight, which represent meridional image plane curvature and sagittal image plane curvature. Fig. 39 shows distortion curves of the optical imaging system of example eight, which represent distortion magnitude values corresponding to different angles of view. Fig. 40 shows a chromatic aberration of magnification curve of the optical imaging system of example eight, which represents deviation of different image heights on the imaging plane after light passes through the optical imaging system.

As can be seen from fig. 37 to 40, the optical imaging system of example eight can achieve good imaging quality.

To sum up, examples one to eight satisfy the relationships shown in table 17, respectively.

Conditional expressions/examples	1	2	3	4	5	6	7	8
									Fno	1.64	1.64	1.64	1.64	1.64	1.64	1.61	1.64
TTL/T56	5.73	5.79	4.75	4.26	4.86	5.79	4.23	4.86
									f5*tan(semi-fov)(mm)	4.98	4.36	5.85	4.24	5.50	4.33	4.28	5.51
f/T56	4.62	4.69	3.83	3.45	3.90	4.69	3.39	3.90
									(TTL-∑CT)/ImgH	0.77	0.75	0.81	0.73	0.82	0.75	0.73	0.82
Fno*Imgh(mm)	7.91	8.03	7.89	8.09	7.94	7.97	7.94	7.97
									f5/f	1.00	0.87	1.17	0.84	1.10	0.87	0.86	1.10
TTL/(f+f6)	3.28	3.39	5.54	4.31	3.48	3.39	4.57	3.48
									f123/f2345	1.39	1.89	1.91	1.81	1.99	1.89	1.78	1.99
(R10-R11)/(R10+R11)	0.14	0.30	-0.21	-0.05	0.14	0.30	-0.05	0.14
									(CT1+T12+CT2+T23+CT3)/CT2	8.01	7.12	6.88	7.94	6.67	7.12	7.94	6.67
SAG51/(SAG61-SAG21)	0.06	-0.10	0.07	0.26	0.39	-0.10	0.26	0.39
									SAG22/ET2	-0.15	0.13	0.16	1.25	0.23	0.13	1.25	0.23
ET4/CT4-ET3/CT3	0.50	-0.88	0.48	-0.74	-0.59	-0.88	-0.74	-0.59
									(CT3+T34+CT4)/∑AT	0.25	0.42	0.24	0.35	0.50	0.42	0.35	0.50
∑CT/TD	0.52	0.52	0.48	0.53	0.47	0.52	0.53	0.47

Table 17 table 18 gives effective focal lengths f1 to f6 of respective lenses of the optical imaging systems of example one to example eight.

Parameter/example	1	2	3	4	5	6	7	8
									TTL(mm)	6.65	6.65	6.65	6.65	6.65	6.60	6.59	6.67
Semi-FOV(°)	43.00	42.99	42.99	43.00	43.00	42.99	43.26	43.00
									ImgH(mm)	4.81	4.88	4.80	4.92	4.84	4.85	4.92	4.85
f(mm)	5.36	5.39	5.36	5.39	5.34	5.35	5.29	5.35
									f1(mm)	6.82	7.95	6.33	10.32	9.63	7.89	10.11	9.66
f2(mm)	-28.40	-329.12	-9.02	28.68	-42.52	-326.69	28.09	-42.66
									f3(mm)	25.47	-44.66	39.35	-63.88	33.63	-44.33	-62.56	33.74
f4(mm)	197.25	50.42	13.77	-110.61	14.00	50.05	-108.97	14.05
									f5(mm)	5.34	4.68	6.28	4.55	5.89	4.64	4.54	5.91
f6(mm)	-3.34	-3.43	-4.16	-3.85	-3.42	-3.40	-3.85	-3.44

Watch 18

The present application also provides an imaging device whose electron photosensitive element may be a photo-coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging apparatus may be a stand-alone imaging device such as a digital camera, or may be an imaging module integrated on a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging system described above.

It is to be understood that the above-described embodiments are only a few, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical imaging system, comprising, in order from an object side to an image side:

a first lens having an optical power;

a second lens having an optical power;

a third lens having optical power;

a fourth lens having a refractive power, a surface of the fourth lens in the vicinity of an object-side optical axis being a convex surface;

a fifth lens having a refractive power, a surface of the fifth lens near an image side optical axis being a convex surface;

a sixth lens having a negative refractive power, a surface of the sixth lens in the vicinity of an object-side optical axis being a concave surface;

wherein, the f-number Fno of the optical imaging system satisfies: fno < 1.7;

the effective focal length f5 of the fifth lens and half semii-Fov of the maximum field angle of the optical imaging system satisfy that: 4mm < f5 tan (semi-Fov) <6.5 mm;

the distance TTL along the optical axis from the surface of the first lens near the object side optical axis to the imaging surface of the optical imaging system and the air gap T56 between the fifth lens and the sixth lens on the optical axis satisfy that: 4< TTL/T56< 6.

2. The optical imaging system of claim 1, wherein the air gap T56 between the fifth lens and the sixth lens on the optical axis and the effective focal length f of the optical imaging system satisfy: 3< f/T56< 5.

3. The optical imaging system according to claim 1, wherein a distance TTL along an optical axis from a surface of the first lens in the vicinity of an object-side optical axis to an imaging surface of the optical imaging system, a sum Σ CT of center thicknesses of all lenses of the first lens to the sixth lens, and a half ImgH of a diagonal length of an effective pixel region on the imaging surface satisfy: 0.5< (TTL-sigma CT)/ImgH < 1.5.

4. The optical imaging system according to claim 1, wherein an f-number Fno of the optical imaging system and a half ImgH of a diagonal length of an effective pixel area on the imaging plane satisfy: 7.5mm < Fno ImgH <9 mm.

5. The optical imaging system of claim 1, wherein an effective focal length f5 of the fifth lens and an effective focal length f of the optical imaging system satisfy: 0.4< f5/f < 1.5.

6. The optical imaging system according to claim 1, wherein a distance TTL along an optical axis from a surface of the first lens in the vicinity of an object-side optical axis to an imaging surface of the optical imaging system, an effective focal length f of the optical imaging system, and an effective focal length f6 of the sixth lens satisfy: 3.0< TTL/(f + f6) < 6.0.

7. The optical imaging system of claim 1, wherein a combined focal length f123 of the first lens, the second lens, and the third lens and a combined focal length f2345 of the second lens, the third lens, the fourth lens, and the fifth lens satisfy: 1.0< f123/f2345< 2.5.

8. The optical imaging system according to claim 1, wherein a radius of curvature R10 of a surface of the fifth lens in the vicinity of an image side optical axis and a radius of curvature R11 of a surface of the sixth lens in the vicinity of an object side optical axis satisfy: -0.5< (R10-R11)/(R10+ R11) < 0.5.

9. The optical imaging system of claim 1, wherein the central thickness CT1 of the first lens, the air gap T12 of the first and second lenses on the optical axis, the central thickness CT2 of the second lens, the air gap T23 of the second and third lenses on the optical axis, the central thickness CT3 of the third lens satisfy: 6.0< (CT1+ T12+ CT2+ T23+ CT3)/CT2< 8.5.

10. An optical imaging system, comprising, in order from an object side to an image side:

a first lens having an optical power;

a second lens having an optical power;

a third lens having optical power;

the diaphragm number Fno of the optical imaging system and the half ImgH of the diagonal length of the effective pixel area on the imaging surface of the optical imaging system satisfy the following condition: 7.5mm < Fno ImgH <9 mm;