CN211905838U

CN211905838U - Optical imaging system

Info

Publication number: CN211905838U
Application number: CN202020523081.4U
Authority: CN
Inventors: 闻人建科; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2020-11-10
Anticipated expiration: 2030-04-10

Abstract

The application discloses optical imaging system, it includes: the lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which have focal power in sequence from the object side to the image side along a first direction; the first prism is arranged at the object side of the lens group and used for reflecting the light rays incident to the first prism along the second direction into the light rays emitted from the first prism along the first direction; the second prism is arranged at the image side of the lens group and used for reflecting the light rays incident to the second prism along the first direction into the light rays emitted from the second prism along the third direction; the first direction, the second direction and the third direction are pairwise vertical; at least one lens in the lens group is a plastic lens, and at least one mirror surface of the plastic lens is an aspheric surface; and wherein the total effective focal length f of the optical imaging system satisfies f > 20 mm.

Description

Optical imaging system

Technical Field

The present application relates to the field of optical elements, and more particularly, to an optical imaging system.

Background

A camera module is generally installed in a portable device such as a mobile phone, so that the mobile phone has a camera function. In recent years, with the upgrade and upgrade of consumer electronics products, image software functions and video software functions on consumer electronics products are developed. The market demand for camera modules suitable for portable electronic products has increased gradually. The camera module is generally provided with an image sensor of a Charge-coupled Device (CCD) type or a Complementary Metal Oxide Semiconductor (CMOS) type, and an optical imaging system. The optical imaging system can collect light beams on the object side, wherein imaging light rays travel along the light path of the optical imaging system and irradiate the image sensor, and then the image sensor converts optical signals into electric signals to form image data.

With the increasing requirements of miniaturized electronic products such as smart phones and the like on imaging functions, higher requirements are also put forward on the optical performance of an optical imaging system. At present, the mobile phone terminal pursues optical zoom factor, and the magnification of the imaging of the optical imaging system is increased after the value of the optical zoom factor is increased, so that a distant scene can be shot more clearly and visibly. However, when the focal length of the optical imaging system is increased, the optical total length of the optical imaging system is also increased, and the optical imaging system with a larger size is disadvantageous to the miniaturization of electronic products such as mobile phones.

In order to meet the miniaturization requirement and meet the imaging requirement, an optical imaging system which can achieve both miniaturization and long focal length and has good imaging quality is required.

SUMMERY OF THE UTILITY MODEL

The present application provides an optical imaging system applicable to portable electronic products that may address, at least in part, at least one of the above-identified deficiencies in the prior art.

A first aspect of the present application provides an optical imaging system comprising: the lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which have focal power in sequence from the object side to the image side along a first direction; the first prism is arranged at the object side of the lens group and used for reflecting the light rays incident to the first prism along the second direction into the light rays emitted from the first prism along the first direction; the second prism is arranged at the image side of the lens group and used for reflecting the light rays incident to the second prism along the first direction into the light rays emitted from the second prism along the third direction; the first direction, the second direction and the third direction are pairwise vertical; at least one lens in the lens group is a plastic lens, and at least one mirror surface of the plastic lens is an aspheric surface; and wherein the total effective focal length f of the optical imaging system satisfies f > 20 mm.

In one embodiment, the total effective focal length f of the optical imaging system and the length Ty of the optical imaging system in the third direction may satisfy 1.0 < f/Ty < 3.0.

In one embodiment, the total effective focal length f of the optical imaging system and the length Tz of the optical imaging system in the second direction may satisfy 2.0 < f/Tz < 4.0.

In one embodiment, f/ImgH > 8 may be satisfied by a total effective focal length f of the optical imaging system and a half ImgH of a diagonal length of an effective pixel area on an imaging plane of the optical imaging system.

In one embodiment, the total effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system may satisfy f/EPD ≦ 4.0.

In one embodiment, the refractive index N1 of the first lens and the refractive index N2 of the second lens can satisfy 0 < N2-N1 < 0.2; the Abbe number V1 of the first lens and the Abbe number V2 of the second lens may satisfy 0 < V1-V2 < 10.

In one embodiment, the Abbe number V4 of the fourth lens and the Abbe number V5 of the fifth lens may satisfy 50 < (V4+ V5)/2 < 60.

In one embodiment, the first lens has a positive optical power; the second lens has positive focal power; the third lens has negative focal power; the fourth lens has positive focal power; the fifth lens has a negative power.

In one embodiment, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens can satisfy 0.1 < f1/f2 < 0.3.

In one embodiment, the total effective focal length f of the optical imaging system and the effective focal length f4 of the fourth lens can satisfy 1.0 < f/f4 < 3.0.

In one embodiment, the effective focal length f3 of the third lens and the effective focal length f5 of the fifth lens may satisfy 2.0 < f3/f5 < 3.0.

In one embodiment, a sum Σ CT of center thicknesses of each of the first lens to the fifth lens may satisfy 1.0mm < Σct/5 < 1.5 mm.

A second aspect of the present application provides an optical imaging system comprising: the lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which have focal power in sequence from the object side to the image side along a first direction; the first prism is arranged at the object side of the lens group and used for reflecting the light rays incident to the first prism along the second direction into the light rays emitted from the first prism along the first direction; the second prism is arranged at the image side of the lens group and used for reflecting the light rays incident to the second prism along the first direction into the light rays emitted from the second prism along the third direction; the first direction, the second direction and the third direction are pairwise vertical; at least one lens in the lens group is a plastic lens, and at least one mirror surface of the plastic lens is an aspheric surface; and wherein f/ImgH > 8 is satisfied by the total effective focal length f of the optical imaging system and half ImgH of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system.

In one embodiment, the total effective focal length f of the optical imaging system and the length Ty of the optical imaging system in the third direction satisfy 1.0 < f/Ty < 3.0.

In one embodiment, the total effective focal length f of the optical imaging system and the length Tz of the optical imaging system in the second direction satisfy 2.0 < f/Tz < 4.0.

In one embodiment, the total effective focal length f of the optical imaging system satisfies f > 20 mm.

In one embodiment, the total effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy f/EPD ≦ 4.0.

In one embodiment, the refractive index of the first lens, N1, and the refractive index of the second lens, N2, satisfy 0 < N2-N1 < 0.2; the Abbe number V1 of the first lens and the Abbe number V2 of the second lens satisfy 0 < V1-V2 < 10.

In one embodiment, the Abbe number V4 of the fourth lens and the Abbe number V5 of the fifth lens satisfy 50 < (V4+ V5)/2 < 60.

In one embodiment, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy 0.1 < f1/f2 < 0.3.

In one embodiment, the total effective focal length f of the optical imaging system and the effective focal length f4 of the fourth lens satisfy 1.0 < f/f4 < 3.0.

In one embodiment, the effective focal length f3 of the third lens and the effective focal length f5 of the fifth lens satisfy 2.0 < f3/f5 < 3.0.

In one embodiment, a sum Σ CT of center thicknesses of the respective lenses of the first lens to the fifth lens satisfies 1.0mm < Σct/5 < 1.5 mm.

This application has adopted first prism and second prism to turn back the optical path, has 90 degrees angles between messenger's object plane and the imaging surface, and then makes optical imaging system optical length on the first direction shorter to make optical imaging system's volume miniaturization. Meanwhile, the optical imaging system has a longer focal length, and further has better optical zoom magnification. And the optical imaging system has better optical imaging quality.

Drawings

Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments when taken in conjunction with the accompanying drawings. In the drawings:

fig. 1 shows a schematic front view of an optical imaging system according to embodiment 1 of the present application;

FIG. 2 shows a schematic top view of an optical imaging system according to embodiment 1 of the present application;

fig. 3 and 4 show an astigmatism curve and a distortion curve, respectively, of the optical imaging system of embodiment 1.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in this specification, the expressions first, second, third, etc. are used only 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 surface of each lens closest to the object is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Moreover, when a statement such as "at least one of" appears after a list of listed features, the entirety of the listed features is modified rather than modifying individual elements in the list. Furthermore, when describing embodiments of the present application, the use of "may" mean "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to an example or illustration.

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

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 application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The features, principles, and other aspects of the present application are described in detail below.

An optical imaging system according to an exemplary embodiment of the present application may include a first prism, a lens group, and a second prism. The three are arranged in sequence from the object side to the image side along the first direction. The lens group may include, for example, five lenses having optical powers, i.e., a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The five lenses are arranged in order from an object side to an image side along an optical axis in a first direction. Any adjacent two lenses among the first to fifth lenses may have an air space therebetween. There may be an air space between the first lens and the first prism. There may be an air space between the fifth lens and the second prism.

The first prism is arranged on the object side of the lens group. Illustratively, the first prism may be a triangular prism including a first incident surface, a first reflecting surface, and a first exit surface. The first reflecting surface forms an included angle of 45 degrees with the first direction. The first emission surface may be perpendicular to the first direction. The second direction is perpendicular to the first direction and forms an included angle of 45 degrees with the first reflecting surface. The first reflecting surface may be configured to reflect light incident in the second direction as light exiting in the first direction. The first incident surface may be perpendicular to the second direction. Illustratively, the first prism may also be a mirror, typically having a first reflective surface.

The second prism is arranged on the image side of the lens group. Illustratively, the second prism may be a triangular prism including a second incident surface, a second reflecting surface, and a second exit surface. The second reflecting surface forms an angle of 45 degrees with the first direction. The second incident surface may be perpendicular to the first direction. The third direction is perpendicular to the first direction and forms an included angle of 45 degrees with the second reflecting surface, and meanwhile the third direction is perpendicular to the second direction. The second reflecting surface is used for reflecting the light rays incident along the first direction into the light rays emitted along the third direction. The second exit face may be perpendicular to the third direction.

The optical path is folded twice by the first prism and the second prism, and the emitting surface of the first prism and the reflecting surface of the second prism have an included angle of about 30 degrees, so that an angle of 90 degrees is formed between the object surface and the imaging surface, and further, the optical length of the optical imaging system in the first direction is short, and the volume of the optical imaging system is miniaturized. Meanwhile, the optical imaging system has a longer focal length, and further has better optical zoom magnification.

In an exemplary embodiment, the optical imaging system may further include at least one diaphragm. The stop may be provided at an appropriate position as required, for example, between the first prism and the first lens. Optionally, the optical imaging system may further include a filter for correcting color deviation and/or a protective glass for protecting the photosensitive element on the imaging surface. The filter and/or the protective glass may be located on the image side of the second prism.

In an exemplary embodiment, at least one lens of the lens group is a plastic lens, and at least one mirror surface of the plastic lens is an aspherical surface. The plastic lens is adopted and has an aspheric surface, so that the design freedom degree of the lens is favorably improved, and meanwhile, the on-axis spherical aberration of the optical imaging system and the off-axis meridional coma aberration thereof can be further reduced. Illustratively, the first lens is a plastic lens, and the object-side surface of the first lens is aspheric.

In the embodiment of the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface, that is, at least one of the object-side surface of the first lens to the image-side surface of the fifth 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 better curvature radius characteristics, 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. Optionally, at least one of an object-side surface and an image-side surface of each of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens is an aspheric mirror surface. Optionally, each of the first, second, third, fourth, and fifth lenses has an object-side surface and an image-side surface that are aspheric mirror surfaces.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression f > 20mm, where f is the total effective focal length of the optical imaging system. By controlling this conditional expression, the optical imaging system can be made to have a long-focus characteristic. Illustratively, f may satisfy f > 22 mm. More specifically, f can satisfy 23mm < f < 25 mm.

In an exemplary embodiment, the lens group includes five lenses, wherein the first lens may have positive optical power; the second lens may have a positive optical power; the third lens may have a negative optical power; the fourth lens may have a positive optical power; the fifth lens may have a negative optical power. Through reasonable positive and negative distribution of focal power of each component of the control system and the lens surface curvature, the temperature drift offset of the long-focus optical imaging system can be effectively reduced, and further the imaging quality of the optical imaging system at different temperatures is improved.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression 1.0 < f/Ty < 3.0, where f is a total effective focal length of the optical imaging system and Ty is a length of the optical imaging system in the third direction. By limiting the conditional expression, the optical path length of the optical imaging system in the third direction is short under the condition that the total effective focal length of the optical imaging system reaches the required magnification, and the size of the optical imaging system can be further reduced. More specifically, f and Ty satisfy 1.3 < f/Ty < 2.0.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression 2.0 < f/Tz < 4.0, where f is a total effective focal length of the optical imaging system, and Tz is a length of the optical imaging system in the second direction. By limiting the conditional expression, the optical path length of the optical imaging system in the second direction is short under the condition that the total effective focal length of the optical imaging system reaches the required magnification, and the size of the optical imaging system can be further reduced. More specifically, f and Tz may satisfy 2.5 < f/Tz < 3.5.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression f/ImgH > 8, where f is the total effective focal length of the optical imaging system and ImgH is half the diagonal length of the effective pixel area on the imaging plane of the optical imaging system. By controlling the ratio of the total effective focal length to the image height, the optical imaging system has enough telephoto capability, and the magnification of a photographed object is improved. More specifically, f and ImgH may satisfy f/ImgH > 9.0.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression f/EPD ≦ 4.0, where f is the total effective focal length of the optical imaging system and EPD is the entrance pupil diameter of the optical imaging system. By controlling the ratio of the total effective focal length to the entrance pupil diameter, the light flux of the super-long focal length type optical imaging lens can be improved, and the signal-to-noise ratio of image data is improved. More specifically, f and EPD may satisfy 3.0 < f/EPD ≦ 4.0.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression 0 < N2-N1 < 0.2, where N1 is the refractive index of the first lens and N2 is the refractive index of the second lens. Illustratively, the optical imaging system of the present application may satisfy the conditional expression 0 < V1-V2 < 10, where V1 is the abbe number of the first lens and V2 is the abbe number of the second lens. The refractive index and the dispersion coefficient of the first lens and the refractive index and the dispersion coefficient of the second lens are controlled to meet the relationship, so that the reduction of the vertical axis chromatic aberration of the optical imaging system is facilitated, and the imaging quality of the optical imaging system is improved. More specifically, N1 and N2 may satisfy 0 < N2-N1 < 0.1. More specifically, V1 and V2 satisfy 5.0 < V1-V2 < 9.0.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression 50 < (V4+ V5)/2 < 60, where V4 is the abbe number of the fourth lens and V5 is the abbe number of the fifth lens. By controlling the dispersion coefficient of the fourth lens and the dispersion coefficient of the fifth lens, the magnification chromatic aberration of the optical imaging system is favorably reduced, the imaging quality of the optical imaging system is improved, and the Modulation Transfer Function (MTF) value is improved. More specifically, V4 and V5 satisfy 55 < (V4+ V5)/2 < 59.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression 0.1 < f1/f2 < 0.3, where f1 is an effective focal length of the first lens and f2 is an effective focal length of the second lens. By controlling the effective focal length ratio of the first lens and the second lens, the distortion of an optical imaging system is favorably reduced, and the deformation of a shot object in an image is further reduced. More specifically, f1 and f2 satisfy 0.15 < f1/f2 < 0.20.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression 1.0 < f/f4 < 3.0, where f is an overall effective focal length of the optical imaging system, and f4 is an effective focal length of the fourth lens. By controlling the ratio of the total effective focal length to the effective focal length of the fourth lens, the tilt sensitivity of the fourth lens is favorably reduced, and the tolerance sensitivity of the optical imaging system to tilt is further reduced. More specifically, f and f4 can satisfy 1.5 < f/f4 < 2.0.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression 2.0 < f3/f5 < 3.0, where f3 is an effective focal length of the third lens and f5 is an effective focal length of the fifth lens. By controlling the ratio of the effective focal length of the third lens to the effective focal length of the fifth lens, the eccentricity sensitivity of the third lens and the eccentricity sensitivity of the fifth lens are reduced, the yield distribution of the optical imaging system is integrally improved, and the optical imaging system is manufactured and produced. More specifically, f3 and f5 satisfy 2.1 < f3/f5 < 2.5.

In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional expression 1.0mm < Σct/5 < 1.5mm, where Σ CT is the sum of the center thicknesses of the respective first to fifth lenses. By controlling the condition, the back focal size of the optical imaging system can be greatly improved, and the optical imaging system is favorable for arranging complex optical path imaging auxiliary systems such as lower prisms, reflectors and the like. Illustratively, Σ CT ═ CT1+ CT2+ CT3+ CT4+ CT5, where CT1 is the center thickness of the first lens. More specifically, Sigma CT may satisfy 1.15mm < SigmaCT/5 < 1.45 mm.

A plurality of lenses, for example, the five lenses described above, may be employed in the lens group of the optical imaging system according to the above-described embodiment of the present application. By reasonably distributing the focal power, the surface type, the central thickness of each lens, the on-axis distance between each lens and the like, the focal length of the system can be effectively increased, the sensitivity of the imaging system can be reduced, and the processability of the imaging system can be improved, so that the optical imaging system is more favorable for production and processing and can be suitable for portable electronic products. Meanwhile, the optical imaging system can be matched with the first prism and the second prism, so that the optical length in the first direction can be compressed, and the optical imaging system can also be used for optical zooming and other functions.

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

Specific examples of the optical imaging system that can be applied to the above-described embodiments are further described below with reference to the drawings.

Example 1

An optical imaging system according to embodiment 1 of the present application is described below with reference to fig. 1 to 4. Fig. 1 shows a schematic front view of an optical imaging system according to embodiment 1 of the present application. Fig. 2 shows a schematic top view.

As shown in fig. 1, the optical imaging system, in order from an object side to an image side along a first direction X, comprises: the lens comprises a first prism P1, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a second prism P2 and a filter E6.

The first prism P1 includes a first incident surface S1, a first reflecting surface S2, and a first exit surface S3, and the first reflecting surface S1 makes an angle of 45 ° with the first direction X. The light L2 incident in the second direction Z is deflected at the first reflection surface S2 as a light ray L1 propagating in the first direction X. The first prism P1 and the first lens E1 also have a stop therebetween.

The first lens element E1 has positive power, and has a convex object-side surface S4 and a concave image-side surface S5. The second lens element E2 has positive power, and has a concave object-side surface S6 and a convex image-side surface S7. The third lens element E3 has negative power, and has a concave object-side surface S8 and a convex image-side surface S9. The fourth lens element E4 has positive power, and has a convex object-side surface S10 and a convex image-side surface S11. The fifth lens element E5 has negative power, and has a convex object-side surface S12 and a concave image-side surface S13.

The second prism P2 includes a second incident surface S14, a second reflecting surface S15 and a second exit surface S16, and the second reflecting surface S15 forms an angle of 45 ° with the first direction X. The light L1 incident in the first direction X is deflected at the second reflecting surface S15 as a light ray L3 traveling in the third direction Y. Meanwhile, the third direction Y is perpendicular to the second direction Z.

Filter E6 has an object side S17 and an image side S18. The optical imaging system has an imaging surface S19, and light from the object (including light L1 at the optical axis in the second direction Z and edge rays) sequentially passes through (or passes through) the respective surfaces S1 to S18 and is finally imaged on the imaging surface S19.

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

TABLE 1

In embodiment 1, the value of the total effective focal length f of the optical imaging system is 24.00mm, and the value of the maximum field angle FOV is 12.6 °.

In embodiment 1, the object-side surface and the image-side surface of any one of the first lens E1 to the fifth lens E5 are aspheric surfaces, and the surface shape x of each aspheric lens can be defined by, but is not limited to, the following aspheric surface 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 shows the high-order term coefficients A that can be used for the aspherical mirror surfaces S4 to S13 in example 1₄、A₆、A₈、A₁₀、A₁₂、A₁₄、A₁₆、A₁₈And A₂₀。

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S4

6.5018E-02

1.9356E-02

4.9292E-04

-6.4124E-05

-1.0449E-04

-3.7724E-05

-4.3844E-05

-2.4528E-05

-8.8362E-06

S5

4.6680E-02

2.7299E-02

-9.0126E-03

-2.8068E-03

-3.4874E-04

6.0546E-05

2.4585E-04

3.1587E-04

7.7389E-05

S6

-6.7682E-02

-2.8107E-02

-1.0635E-03

-5.6094E-04

2.3210E-03

1.0103E-03

1.0544E-03

5.8282E-04

5.2065E-05

S7

-2.5958E-01

5.4885E-02

-2.2406E-02

6.0319E-03

-8.7768E-03

3.6553E-03

-1.4870E-03

-2.0575E-03

1.1907E-03

S8

-2.9115E-02

3.0192E-02

1.7983E-03

-6.0309E-03

-6.9128E-04

-5.4877E-04

2.0005E-04

-1.3706E-04

-1.1574E-04

S9

1.7447E-01

-9.0705E-02

5.2802E-02

-2.1087E-02

4.8637E-03

-2.4433E-03

1.2569E-03

-2.0754E-04

-1.3693E-04

S10

1.1088E-02

4.1038E-03

-6.7942E-03

3.5531E-04

-1.5298E-04

1.0088E-04

-4.0030E-04

2.9430E-05

6.4232E-05

S11

1.6933E-03

-1.0495E-02

6.8909E-03

-5.0012E-04

2.3296E-04

-6.9774E-04

-2.4324E-04

1.1347E-04

7.3324E-05

S12

-3.3023E-01

3.2598E-03

1.9951E-02

-2.5149E-02

1.2605E-02

-2.3112E-03

-1.5124E-03

3.7053E-04

1.6117E-04

S13

-4.4666E-01

-5.2210E-02

8.3730E-03

-1.4385E-02

5.6913E-03

-1.3423E-03

1.3683E-04

-6.2066E-04

3.2276E-04

TABLE 2

Fig. 3 shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical imaging system of embodiment 1. Fig. 4 shows distortion curves of the optical imaging system of embodiment 1, which represent distortion magnitude values corresponding to different image heights. As can be seen from fig. 3 and 4, the optical imaging system according to embodiment 1 can achieve good imaging quality.

In summary, example 1 satisfies the relationship shown in table 3.

TABLE 3

The present application also provides an imaging Device, which is provided with an electron sensing element to form an image, wherein the electron sensing element may be a Charge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS). The imaging device 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.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of protection covered by the present application is not limited to the embodiments with a specific combination of the features described above, but also covers other embodiments with any combination of the features described above or their equivalents without departing from the scope of the present application. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. An optical imaging system, comprising: the lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which have focal power in sequence from an object side to an image side along a first direction;

the first prism is arranged on the object side of the lens group and used for reflecting light rays entering the first prism along a second direction to be emitted from the first prism along the first direction;

the second prism is arranged on the image side of the lens group and used for reflecting the light rays incident to the second prism along the first direction to be emitted from the second prism along a third direction;

wherein the first direction, the second direction and the third direction are perpendicular to each other;

at least one lens in the lens group is a plastic lens, and at least one mirror surface of the plastic lens is an aspheric surface; and

wherein the total effective focal length f of the optical imaging system satisfies f > 20 mm.

2. The optical imaging system of claim 1, wherein a total effective focal length f of the optical imaging system and a length Ty of the optical imaging system in the third direction satisfy 1.0 < f/Ty < 3.0.

3. The optical imaging system of claim 1, wherein a total effective focal length f of the optical imaging system and a length Tz of the optical imaging system in the second direction satisfy 2.0 < f/Tz < 4.0.

4. The optical imaging system according to claim 1, wherein f/ImgH > 8 is satisfied by a total effective focal length f of the optical imaging system and a half ImgH of a diagonal length of an effective pixel area on an imaging plane of the optical imaging system.

5. The optical imaging system of claim 1, wherein the total effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy f/EPD ≦ 4.0.

6. The optical imaging system according to claim 1, wherein a refractive index N1 of the first lens and a refractive index N2 of the second lens satisfy 0 < N2-N1 < 0.2;

the Abbe number V1 of the first lens and the Abbe number V2 of the second lens satisfy 0 < V1-V2 < 10.

7. The optical imaging system of claim 1, wherein the abbe number V4 of the fourth lens and the abbe number V5 of the fifth lens satisfy 50 < (V4+ V5)/2 < 60.

8. The optical imaging system of any of claims 1 to 7, wherein the first lens has a positive optical power;

the second lens has positive optical power;

the third lens has a negative optical power;

the fourth lens has positive optical power;

the fifth lens has a negative power.

9. The optical imaging system of claim 8, wherein the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy 0.1 < f1/f2 < 0.3.

10. The optical imaging system of claim 8, wherein the total effective focal length f of the optical imaging system and the effective focal length f4 of the fourth lens satisfy 1.0 < f/f4 < 3.0.

11. The optical imaging system of claim 8, wherein the effective focal length f3 of the third lens and the effective focal length f5 of the fifth lens satisfy 2.0 < f3/f5 < 3.0.

12. The optical imaging system according to claim 8, wherein a sum Σ CT of central thicknesses of the respective lenses of the first to fifth lenses satisfies 1.0mm < Σct/5 < 1.5 mm.

13. An optical imaging system, comprising: the lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which have focal power in sequence from an object side to an image side along a first direction;

wherein, the total effective focal length f of the optical imaging system and the half of the diagonal length ImgH of the effective pixel area on the imaging surface of the optical imaging system satisfy f/ImgH > 8.

14. The optical imaging system of claim 13, wherein a total effective focal length f of the optical imaging system and a length Ty of the optical imaging system in the third direction satisfy 1.0 < f/Ty < 3.0.

15. The optical imaging system of claim 13, wherein a total effective focal length f of the optical imaging system and a length Tz of the optical imaging system in the second direction satisfy 2.0 < f/Tz < 4.0.

16. The optical imaging system of claim 15, wherein the total effective focal length f of the optical imaging system satisfies f > 20 mm.

17. The optical imaging system of claim 13, wherein the total effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy f/EPD ≦ 4.0.

18. The optical imaging system of claim 13, wherein the refractive index N1 of the first lens and the refractive index N2 of the second lens satisfy 0 < N2-N1 < 0.2;

19. The optical imaging system of claim 13, wherein the abbe number V4 of the fourth lens and the abbe number V5 of the fifth lens satisfy 50 < (V4+ V5)/2 < 60.

20. The optical imaging system of any of claims 13 to 19, wherein the first lens has a positive optical power;

the second lens has positive optical power;

the third lens has a negative optical power;

the fourth lens has positive optical power;

the fifth lens has a negative power.

21. The optical imaging system of claim 20, wherein the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy 0.1 < f1/f2 < 0.3.

22. The optical imaging system of claim 20, wherein the total effective focal length f of the optical imaging system and the effective focal length f4 of the fourth lens satisfy 1.0 < f/f4 < 3.0.

23. The optical imaging system of claim 20, wherein the effective focal length f3 of the third lens and the effective focal length f5 of the fifth lens satisfy 2.0 < f3/f5 < 3.0.

24. The optical imaging system according to claim 20, wherein a sum Σ CT of central thicknesses of the respective lenses of the first to fifth lenses satisfies 1.0mm < Σct/5 < 1.5 mm.