CN214375512U

CN214375512U - Optical imaging system, identification module and electronic device

Info

Publication number: CN214375512U
Application number: CN202120170784.8U
Authority: CN
Inventors: 崔甲臣; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2021-01-21
Filing date: 2021-01-21
Publication date: 2021-10-08
Anticipated expiration: 2031-01-21

Abstract

The utility model discloses an optical imaging system, optical imaging system includes according to the preface by thing side to image side along the optical axis: a first lens having a negative refractive power, an object side surface of which is a concave surface; a second lens having a positive optical power; a third lens having a positive optical power; the effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging lens meet the following requirements: f/EPD < 1.6; the effective focal length f2 of the second lens and the effective focal length f1 of the first lens satisfy the following conditional expression: l f2/f1 l < 1.4; the effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy the following conditional expression: 0.5< f2/f3< 1.7. The utility model provides an optical imaging system, through the angle of vision of control camera lens, the F number of system can make the camera lens have great imaging range, retrains first lens thing side to the distance of imaging plane, the ratio of imaging plane effective pixel diagonal length half and third lens effective focal length, and is small, and the angle of vision is big, and the light ring is big, has good imaging quality.

Description

Optical imaging system, identification module and electronic device

Technical Field

The utility model belongs to the optical imaging field especially relates to an optical imaging system, identification module and electron device including three lens.

Background

The mobile phone screen is mainly divided into a Liquid Crystal Display (LCD) screen and an organic light-emitting diode (OLED) screen according to the type of a light source, and the OLED screen has good light transmittance, so that the under-screen fingerprint identification device can receive reflected light formed by reflection of a finger and emitted by the OLED screen to detect a fingerprint. The fingerprint recognition device needs to match a corresponding optical system, the traditional optical system has poor imaging quality due to the factors of large volume, small field angle, small aperture and the like, and the working effect of the recognition device is influenced, so that the prior recognition device needs to be optimized, and the optical imaging system with small volume, large field angle and large aperture is needed and has good imaging quality.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an optical imaging system that three lens are constituteed, this optical imaging system is small, and the angle of vision is big, and the light ring is big, has good formation of image quality.

An aspect of the present invention provides an optical imaging system, which includes, along an optical axis, from an object side to an image side according to a predetermined order: a first lens having a negative refractive power, an object side surface of which is a concave surface; a second lens having a positive optical power; a third lens having a positive optical power.

The effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging lens meet the following requirements: f/EPD < 1.6; the effective focal length f2 of the second lens and the effective focal length f1 of the first lens satisfy the following conditional expression: i f2/f 1I < 1.4.

According to an embodiment of the present invention, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the effective focal length f1 of the first lens satisfy: 2.0< | (f2+ f3)/f1| < 2.5.

According to an embodiment of the present invention, the effective focal length f3 of the third lens, the curvature radius R5 of the object side surface of the third lens, and the curvature radius R6 of the image side surface of the third lens satisfy: -1.6< f3/R5+ f3/R6< -0.9.

According to an embodiment of the present invention, half of the Semi-FOV of the maximum field angle of the optical imaging system satisfies: Semi-FOV >70 deg.

According to an embodiment of the present invention, the central thickness CT3 of the third lens on the optical axis and the edge thickness ET3 of the third lens satisfy: 1.5< CT3/ET3< 2.1.

According to the utility model discloses an embodiment, the high YO of the thing of the maximum imaging height of optical imaging system satisfies with the imaging area on the regional diagonal length of effective pixel half ImgH: 4.0< YO/ImgH < 5.5.

According TO an embodiment of the present invention, the on-axis distance TD between the object-side surface of the first lens element and the image-side surface of the last lens element and the distance TO between the object and the object-side surface of the first lens element on the optical axis satisfy: 0.5< TD/TO < 1.0.

According to the utility model discloses an embodiment, the epaxial distance SL of light ring to imaging surface satisfies: 1.0mm < SL <1.5 mm.

According to an embodiment of the present invention, the axial distance SAG12 between the intersection point of the first lens image side surface and the optical axis and the effective radius vertex of the first lens image side surface and the air space T12 on the optical axis between the first lens and the second lens satisfy: 1.0< SAG12/T12< 1.5.

According to an embodiment of the present invention, the optical imaging system further includes a glass screen disposed between the object side and the first lens.

Another aspect of the present invention provides an optical imaging system, which includes, along an optical axis, from an object side to an image side according to a predetermined order: a first lens having a negative refractive power, an object side surface of which is a concave surface; a second lens having an optical power; the third lens with focal power has a convex object-side surface and a convex image-side surface.

Wherein, each lens is independent, and there is air space on the optical axis between each lens; the effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy: 0.5< f2/f3< 1.7.

Another aspect of the present invention provides an identification module, including the above-mentioned optical imaging system and an electronic photosensitive element, wherein the electronic photosensitive element is disposed on an image plane of the optical imaging system.

Yet another aspect of the present invention provides an electronic device, including the above-mentioned identification module.

The utility model has the advantages that:

the utility model provides an optical imaging system includes multi-disc lens, like first lens to third lens. The utility model discloses an optical imaging system is small, and the angle of vision is big, and the light ring is big, has good formation of image quality.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic view of a lens assembly structure of an embodiment 1 of an optical imaging system according to the present invention;

fig. 2a to fig. 2c are an axial chromatic aberration curve, a distortion curve, and a magnification chromatic aberration curve, respectively, according to embodiment 1 of the optical imaging system of the present invention;

fig. 3 is a schematic view of a lens assembly structure of an embodiment 2 of an optical imaging system according to the present invention;

fig. 4a to 4c are an axial chromatic aberration curve, a distortion curve, and a magnification chromatic aberration curve, respectively, according to embodiment 2 of the optical imaging system of the present invention;

fig. 5 is a schematic view of a lens assembly structure according to embodiment 3 of the optical imaging system of the present invention;

fig. 6a to 6c are an axial chromatic aberration curve, a distortion curve, and a magnification chromatic aberration curve, respectively, according to embodiment 3 of the optical imaging system of the present invention;

fig. 7 is a schematic view of a lens assembly structure according to embodiment 4 of the optical imaging system of the present invention;

fig. 8a to 8c are an axial chromatic aberration curve, a distortion curve, and a magnification chromatic aberration curve, respectively, according to embodiment 4 of the optical imaging system of the present invention;

fig. 9 is a schematic view of a lens assembly structure according to embodiment 5 of the optical imaging system of the present invention;

fig. 10a to 10c are an axial chromatic aberration curve, a distortion curve, and a magnification chromatic aberration curve, respectively, according to embodiment 5 of the optical imaging system of the present invention;

fig. 11 is a schematic diagram of YO and TO parameters of the optical imaging system of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

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 invention.

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.

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.

In the description of the present invention, the paraxial region means 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.

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, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict. Features, principles and other aspects of the present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

Exemplary embodiments

The optical imaging system of the exemplary embodiment of the present invention includes three lenses, and includes in order from the object side to the image side along the optical axis: the lens comprises a first lens, a second lens and a third lens, wherein the lenses are independent from each other, and an air space is formed between the lenses on an optical axis.

In the present exemplary embodiment, the first lens has a negative power, and the object-side surface thereof is a concave surface; the second lens may have a positive or negative optical power; the third lens may have a positive power or a negative power.

In the present exemplary embodiment, the effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging lens satisfy the conditional expression: f/EPD < 1.6. By controlling the angle of view of the lens, the F number of the system is reduced, and the lens can have a larger imaging range. More specifically, f and EPD satisfy: 1< f/EPD <1.55, e.g., 1.44 ≦ f/EPD ≦ 1.51.

In the present exemplary embodiment, the effective focal length f2 of the second lens and the effective focal length f1 of the first lens satisfy the conditional expression: i f2/f 1I < 1.4. More specifically, f2 and f1 satisfy: 1< | f2/f1| <1.38, for example, 1.05 ≦ f2/f1| ≦ 1.36.

In the present exemplary embodiment, the effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy the conditional expression: 0.5< f2/f3< 1.7. The spherical aberration and the coma aberration generated by the second lens and the third lens can be effectively balanced, so that the contribution amount of the spherical aberration and the coma aberration of the balanced second lens and the balanced third lens is in a reasonable range, and the sensitivity of the optical system is in a reasonable level; by controlling the angle of view of the lens, the lens can have a larger imaging range. More specifically, f2 and f3 satisfy: 0.9< f2/f3<1.5, e.g., 0.99. ltoreq. f2/f 3. ltoreq.1.45.

In the present exemplary embodiment, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the effective focal length f1 of the first lens satisfy the conditional expression: 2.0< | (f2+ f3)/f1| < 2.5. By constraining the ratio of the effective focal length of the first lens element to the sum of the effective focal lengths of the first lens and the third lens to be within a certain range, it can be ensured that the optical lens has good processability. More specifically, f2, f3 and f1 satisfy: 2.1< | (f2+ f3)/f1| <2.4, for example, 2.11 ≦ | (f2+ f3)/f1 ≦ 2.36.

In the present exemplary embodiment, the effective focal length f3 of the third lens, the radius of curvature R5 of the object-side surface of the third lens, and the radius of curvature R6 of the image-side surface of the third lens satisfy the conditional expression: -1.6< f3/R5+ f3/R6< -0.9. By restricting the effective focal length of the third lens and the curvature radius of the object side surface of the third lens within a certain range, the focal power of the system can be reasonably distributed, the third-order astigmatism of the system can be controlled within a certain range, and the astigmatism generated by the front-end optics and the back-end optics of the system is balanced, so that the system has good imaging quality. More specifically, f3, R5 and R6 satisfy: -1.55< f3/R5+ f3/R6< -1, for example, -1.52. ltoreq. f3/R5+ f 3/R6. ltoreq. -1.17.

In the present exemplary embodiment, the Semi-FOV, which is half the maximum field angle of the optical imaging system, satisfies the conditional expression: Semi-FOV >70 deg. By controlling the angle of view of the lens, the F number of the system is reduced, and the lens can have a larger imaging range. More specifically, the Semi-FOV satisfies: 70.2 < Semi-FOV <81 °, e.g., 70.31 ≦ Semi-FOV ≦ 80.25 °.

In the present exemplary embodiment, the central thickness CT3 of the third lens on the optical axis and the edge thickness ET3 of the third lens satisfy the conditional expression: 1.5< CT3/ET3< 2.1. By restricting the ratio of the thickness of the middle part of the third lens to the thickness of the edge of the third lens within a certain range, the thickness sensitivity of the lens can be reduced, and the curvature of field can be corrected. More specifically, CT3 and ET3 satisfy: 1.6< CT3/ET3<2, e.g., 1.67. ltoreq. CT3/ET 3. ltoreq.1.89.

In the present exemplary embodiment, the conditional expression that the object height YO of the maximum imaging height of the optical imaging system and the half ImgH of the diagonal length of the effective pixel area on the imaging plane satisfy is: 4.0< YO/ImgH < 5.5. A larger visual angle of the optical imaging system is obtained by restricting the ratio of the object height of the maximum imaging height of the optical image pickup lens group to half of the diagonal length of the effective pixel area on the imaging surface. More specifically, YO and ImgH satisfy: 4.3< YO/ImgH <5.4, e.g., 4.41. ltoreq. YO/ImgH. ltoreq.5.38.

In the present exemplary embodiment, the conditional expression that the on-axis distance TD from the object-side surface of the first lens TO the image-side surface of the last lens and the distance TO from the object TO the object-side surface of the first lens on the optical axis satisfy: 0.5< TD/TO < 1.0. The distance between the image side surface and the object side surface of the first lens on the axis is reasonably configured, so that the thickness sensitivity of the lens can be effectively reduced, and the curvature of field can be corrected. More specifically, TD and TO satisfy: 0.6< TD/TO <0.95, e.g., 0.77. ltoreq. TD/TO. ltoreq.0.94.

In the present exemplary embodiment, the on-axis distance SL from the diaphragm to the imaging plane satisfies the conditional expression: 1.0mm < SL <1.5 mm. The distance between the diaphragm and the imaging surface on the axis is reasonably controlled within a certain range, so that the chief ray angle of the optical imaging lens is adjusted, the relative brightness of the optical imaging lens group can be effectively improved, and the image surface definition is improved. More specifically, SL satisfies: 1.2mm < SL <1.4mm, e.g., 1.27mm ≦ SL ≦ 1.34 mm.

In the present exemplary embodiment, the on-axis distance SAG12 between the intersection of the first lens image-side surface and the optical axis to the effective radius vertex of the first lens image-side surface and the air interval T12 on the optical axis of the first lens and the second lens satisfy the conditional expression: 1.0< SAG12/T12< 1.5. The distance on the axle between the second lens image side face and the point of intersect of optical axis to the effective radius summit of second lens image side face and the air interval of first lens and second lens on the optical axis are in certain range in reasonable control to this adjustment optical imaging lens's chief ray angle can effectively improve optical imaging lens group's relative luminance, promotes image plane definition. More specifically, SAG12 and T12 satisfy: 1.1< SAG12/T12<1.3, e.g., 1.16. ltoreq. SAG 12/T12. ltoreq.1.22.

In the present exemplary embodiment, the above-described optical imaging system may further include a glass screen disposed between the object side and the first lens. The above-described optical imaging system may further include a diaphragm, which may be disposed at an appropriate position as needed, for example, the diaphragm may be disposed between the object side 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 optical imaging system according to the above embodiment of the present invention may employ a plurality of lenses, for example, the three lenses described above. The optical imaging system has a large imaging image surface by reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the on-axis distance between each lens and the like, has the characteristics of wide imaging range and high imaging quality, and ensures the ultrathin property of the mobile phone.

In an exemplary embodiment, at least one of the mirror surfaces of each lens is an aspheric mirror surface, i.e., at least one of the object side surface of the first lens to the image side surface of the third lens is an aspheric mirror surface. The aspheric lens is characterized in that: the aspherical lens has a better curvature radius characteristic, and has advantages of improving distortion aberration and astigmatic aberration, unlike a spherical lens having a constant curvature from the lens center to the lens periphery, in which the curvature is continuously varied from the lens center to the lens periphery. 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 the object-side surface and the image-side surface of each of the first lens, the second lens, and the third lens is an aspheric mirror surface. Optionally, the object-side surface and the image-side surface of each of the first lens, the second lens and the third lens are aspheric mirror surfaces.

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 three lenses are exemplified in the embodiment, the optical imaging system is not limited to include three lenses, and the optical imaging system may include other numbers of lenses if necessary.

Specific embodiments of an optical imaging system suitable for use in the above-described embodiments are further described below with reference to the drawings.

Detailed description of the preferred embodiment 1

Fig. 1 is a schematic view of a lens assembly according to embodiment 1 of the present invention, wherein the optical imaging system sequentially includes, from an object side to an image side along an optical axis: a glass screen E1, a first lens E2, a second lens E3, a stop STO, a third lens E4, a filter E5 and an image plane S11.

Glass screen E1 has an object side S1 and an image side S2. The first lens element E2 has negative power, and has a concave object-side surface S3 and a concave image-side surface S4. The second lens element E3 has positive power, and has a convex object-side surface S5 and a convex image-side surface S6. The third lens element E4 has positive power, and has a convex object-side surface S7 and a convex image-side surface S8. Filter E5 has an object side S9 and an image side S10. The light from the object sequentially passes through the respective surfaces S1 to S10 and is finally imaged on the imaging plane S11.

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

TABLE 1

As shown in table 2, in embodiment 1, the total effective focal length f of the optical imaging system is 0.33mm, the distance TTL on the optical axis from the object-side surface S3 of the first lens E2 to the imaging surface S11 is 2.55mm, the half ImgH of the diagonal line length of the effective pixel region on the imaging surface S11 is 1.03mm, and the half semifov of the maximum field angle of the optical imaging system is 70.31 °.

TABLE 2

The optical imaging system in embodiment 1 satisfies:

f/EPD is 1.44, wherein f is the effective focal length of the optical imaging lens, and EPD is the entrance pupil diameter of the optical imaging lens;

the Semi-FOV is 70.31 °, wherein the Semi-FOV is half of the maximum field angle of the optical imaging system;

1.05, wherein f2 is the effective focal length of the second lens, and f1 is the effective focal length of the first lens;

f2/f3 is 0.99, wherein f2 is the effective focal length of the second lens, and f3 is the effective focal length of the third lens;

(f2+ f3)/f1| -2.11, where f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, and f 1;

f3/R5+ f3/R6 is-1.37, wherein f3 is the effective focal length of the third lens, R5 is the curvature radius of the object-side surface of the third lens, and R6 is the curvature radius of the image-side surface of the third lens;

CT3/ET3 is 1.67, where CT3 is the central thickness of the third lens on the optical axis and ET3 is the edge thickness of the third lens;

YO/ImgH is 4.41, wherein YO is the object height of the maximum imaging height of the optical imaging system, and ImgH is half of the diagonal length of the effective pixel area on the imaging surface;

TD/TO is 0.89, wherein TD is the distance on the axis from the object side surface of the first lens TO the image side surface of the last lens, and TO is the distance on the optical axis from the object TO the object side surface of the first lens;

SL is 1.32mm, where SL is the on-axis distance from the aperture to the imaging plane;

SAG12/T12 is 1.18, wherein SAG12 is an on-axis distance between an intersection point of an image side surface of the first lens and an optical axis and an effective radius vertex of the image side surface of the first lens, and T12 is an air interval between the first lens and the second lens on the optical axis.

In embodiment 1, the object-side surface and the image-side surface of any one of the first lens E2 through the third lens E4 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); k is a conic coefficient; ai is the correction coefficient of the i-th order of the aspheric surface.

In embodiment 1, the object-side surface and the image-side surface of any one of the first lens E2 to the third lens E4 are aspheric3 shows the high-order term coefficients A which can be used for the aspherical mirror surfaces S3 to S8 in example 1₄、A₆、A₈、A₁₀、A₁₂、A₁₄、A₁₆、A₁₈、A₂₀、A₂₂、A₂₄、A₂₆、A₂₈And A₃₀。

Flour mark

A4

A6

A8

A10

A12

A14

A16

S3

1.8933E+00

-4.2969E-01

1.4225E-01

-5.6213E-02

2.5341E-02

-1.2317E-02

6.2690E-03

S4

3.9451E-01

-1.1797E-01

2.8260E-02

2.7453E-03

1.3978E-03

-2.7813E-03

6.3047E-04

S5

-1.2615E-01

5.6973E-03

-4.1004E-03

4.6840E-03

-1.1101E-03

1.6701E-03

-8.6935E-04

S6

5.1861E-02

-1.4798E-02

7.5903E-04

-1.6728E-03

-2.0316E-05

-6.0562E-04

-2.2130E-04

S7

-1.0817E-02

3.9267E-03

-1.2750E-03

7.1761E-04

-4.2780E-04

5.8909E-04

-1.8233E-04

S8

1.8562E-01

2.8519E-02

1.0567E-02

-8.7479E-03

1.1402E-03

3.5272E-04

1.6035E-03

Flour mark

A18

A20

A22

A24

A26

A28

A30

S3

-3.2871E-03

1.7625E-03

-9.5577E-04

5.4204E-04

-2.8704E-04

1.0210E-04

-1.6273E-05

S4

3.7490E-04

1.2168E-03

-1.1731E-04

-8.8593E-04

-1.9689E-03

-1.3117E-03

-8.2552E-04

S5

3.6613E-04

-3.6140E-04

5.4467E-04

2.3982E-04

5.3290E-04

1.4251E-04

2.1336E-04

S6

6.8574E-07

1.5446E-04

-1.4298E-04

-4.6340E-06

1.2709E-05

9.4208E-05

-4.8473E-05

S7

7.4251E-05

-9.8747E-05

-2.2698E-04

-8.5808E-06

2.0076E-05

-1.1598E-04

1.6957E-04

S8

-1.1288E-03

-9.4516E-04

-2.5090E-04

2.6292E-04

-9.0256E-04

-1.0046E-04

2.4686E-04

TABLE 3

Fig. 2a shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 1, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 2b shows a distortion curve of the optical imaging system of embodiment 1, which represents distortion magnitude values corresponding to different image heights. Fig. 2c shows a chromatic aberration of magnification curve of the optical imaging system of embodiment 1, which represents the deviation of different image heights on the imaging plane after the light passes through the lens. As can be seen from fig. 2a to 2c, the optical imaging system according to embodiment 1 can achieve good imaging quality.

Specific example 2

Fig. 3 is a schematic diagram of a lens assembly structure according to embodiment 2 of the present invention, wherein the optical imaging system sequentially includes, from an object side to an image side along an optical axis: a glass screen E1, a first lens E2, a second lens E3, a stop STO, a third lens E4, a filter E5 and an image plane S11.

As shown in table 4, a basic parameter table of the optical imaging system of example 2 is shown, in which the units of the radius of curvature, the thickness, and the focal length are all millimeters (mm).

Flour mark	Surface type	Radius of curvature	Thickness/distance	Focal length	Refractive index	Coefficient of dispersion	Coefficient of cone
								OBJ	Spherical surface	All-round	0.0000
S1	Spherical surface	All-round	1.0000		1.52	64.2	0.0000
								S2	Spherical surface	All-round	1.0818				0.0000
S3	Aspherical surface	-0.4990	0.5184	-0.64	1.54	56.1	-1.0000
								S4	Aspherical surface	1.5711	0.2795				0.0000
S5	Aspherical surface	0.5869	0.4244	0.87	1.62	25.9	0.0000
								S6	Aspherical surface	-2.0000	0.0500				0.0000
STO	Spherical surface	All-round	0.0442				0.0000
								S7	Aspherical surface	1.9166	0.4231	0.64	1.54	56.1	0.0000
S8	Aspherical surface	-0.3907	0.3915				-1.0000
								S9	Spherical surface	All-round	0.2100		1.52	64.2	0.0000
S10	Spherical surface	All-round	0.1962				0.0000
								S11	Spherical surface	All-round

TABLE 4

As shown in table 5, in embodiment 2, the total effective focal length f of the optical imaging system is 0.34mm, the distance TTL on the optical axis from the object-side surface S3 of the first lens E2 to the imaging surface S11 is 2.54mm, the half ImgH of the diagonal line length of the effective pixel region on the imaging surface S11 is 1.02mm, and the half semifov of the maximum field angle of the optical imaging system is 79.34 °. The parameters of each relation are as explained in the first embodiment, and the values of each relation are as listed in the following table.

TABLE 5

In example 2, the object-side surface and the image-side surface of any one of the first lens E2 to the third lens E4 are aspheric, and table 6 shows the high-order term coefficients a that can be used for the aspheric mirror surfaces S3 to S8 in example 2₄、A₆、A₈、A₁₀、A₁₂、A₁₄、A₁₆、A₁₈、A₂₀、A₂₂、A₂₄、A₂₆、A₂₈And A₃₀。

Flour mark

A4

A6

A8

A10

A12

A14

A16

S3

2.0325E+00

-4.6218E-01

1.5387E-01

-6.1758E-02

2.8187E-02

-1.3913E-02

7.1869E-03

S4

3.8935E-01

-1.1235E-01

3.4057E-02

4.6142E-03

3.9659E-05

-3.5964E-03

1.4148E-03

S5

-1.3032E-01

5.0675E-03

-2.2258E-03

4.7667E-03

-1.1765E-03

1.3486E-03

-8.0274E-04

S6

1.0766E-01

-4.1994E-02

1.4908E-02

-1.0186E-02

1.0800E-02

-4.5736E-03

-1.7840E-03

S7

-8.6108E-03

5.4545E-03

-2.5775E-03

4.4477E-04

-1.8725E-05

7.3179E-04

-4.8526E-05

S8

2.2112E-01

1.9428E-02

7.2245E-04

-5.3791E-03

3.1213E-03

6.5449E-04

-1.0476E-04

Flour mark

A18

A20

A22

A24

A26

A28

A30

S3

-3.8552E-03

2.1409E-03

-1.1967E-03

6.9064E-04

-3.8557E-04

1.5104E-04

-2.6581E-05

S4

1.2439E-03

1.4016E-03

-6.4554E-04

-1.3523E-03

-1.8045E-03

-9.6054E-04

-5.1698E-04

S5

4.4186E-04

-2.5803E-04

5.1722E-04

1.9494E-04

5.1867E-04

1.9290E-04

2.2139E-04

S6

1.5395E-03

1.1077E-03

-8.9611E-04

-9.4650E-04

1.0541E-03

-6.8668E-05

-3.3866E-04

S7

-1.1001E-04

-4.0873E-04

-1.3198E-04

-1.8962E-05

1.5745E-04

1.2102E-04

9.2800E-05

S8

-1.6151E-03

1.7121E-04

1.9986E-04

-1.0079E-04

-1.0028E-03

-7.0628E-04

-3.9907E-04

TABLE 6

Fig. 4a shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 2, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 4b shows a distortion curve of the optical imaging system of embodiment 2, which represents distortion magnitude values corresponding to different image heights. Fig. 4c shows a chromatic aberration of magnification curve of the optical imaging system of embodiment 2, which represents the deviation of different image heights on the imaging plane after the light passes through the lens. As can be seen from fig. 4a to 4c, the optical imaging system according to embodiment 2 can achieve good imaging quality.

Specific example 3

Fig. 5 is a schematic view of a lens assembly according to embodiment 3 of the present invention, wherein the optical imaging system sequentially includes, from an object side to an image side along an optical axis: a glass screen E1, a first lens E2, a second lens E3, a stop STO, a third lens E4, a filter E5 and an image plane S11.

As shown in table 7, a basic parameter table of the optical imaging system of example 3 is shown, in which the units of the radius of curvature, the thickness, and the focal length are all millimeters (mm).

TABLE 7

As shown in table 8, in embodiment 3, the total effective focal length f of the optical imaging system is 0.32mm, the distance TTL on the optical axis from the object-side surface S3 of the first lens E2 to the imaging surface S11 is 2.58mm, the half ImgH of the diagonal line length of the effective pixel region on the imaging surface S11 is 1.02mm, and the half semifov of the maximum field angle of the optical imaging system is 78.34 °. The parameters of each relation are as explained in the first embodiment, and the values of each relation are as listed in the following table.

TABLE 8

In embodiment 3, the object-side surface and the image-side surface of any one of the first lens E2 to the third lens E4 are aspheric, and table 9 showsThe high-order term coefficients A usable for the aspherical mirror surfaces S3 to S8 in example 3 are shown₄、A₆、A₈、A₁₀、A₁₂、A₁₄、A₁₆、A₁₈、A₂₀、A₂₂、A₂₄、A₂₆、A₂₈And A₃₀。

TABLE 9

Fig. 6a shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 3, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 6b shows a distortion curve of the optical imaging system of embodiment 3, which represents distortion magnitude values corresponding to different image heights. Fig. 6c shows a chromatic aberration of magnification curve of the optical imaging system of embodiment 3, which represents the deviation of different image heights on the imaging plane after the light passes through the lens. As can be seen from fig. 6a to 6c, the optical imaging system according to embodiment 3 can achieve good imaging quality.

Specific example 4

Fig. 7 is a schematic diagram of a lens assembly structure according to embodiment 4 of the present invention, wherein the optical imaging system sequentially includes, from an object side to an image side along an optical axis: a glass screen E1, a first lens E2, a second lens E3, a stop STO, a third lens E4, a filter E5 and an image plane S11.

Glass screen E1 has an object side S1 and an image side S2. The first lens element E2 has negative power, and has a concave object-side surface S3 and a concave image-side surface S4. The second lens element E3 has positive power, and has a convex object-side surface S5 and a concave image-side surface S6. The third lens element E4 has positive power, and has a convex object-side surface S7 and a convex image-side surface S8. Filter E5 has an object side S9 and an image side S10. The light from the object sequentially passes through the respective surfaces S1 to S10 and is finally imaged on the imaging plane S11.

As shown in table 10, the basic parameter table of the optical imaging system of example 4 is shown, in which the units of the radius of curvature, the thickness, and the focal length are all millimeters (mm).

Flour mark	Surface type	Radius of curvature	Thickness/distance	Focal length	Refractive index	Coefficient of dispersion	Coefficient of cone
								OBJ	Spherical surface	All-round	0.0000
S1	Spherical surface	All-round	1.0000		1.52	64.2	0.0000
								S2	Spherical surface	All-round	0.9562				0.0000
S3	Aspherical surface	-33.4390	0.5000	-0.66	1.54	56.1	-1.0000
								S4	Aspherical surface	1.6777	0.2752				0.0000
S5	Aspherical surface	0.5592	0.4165	0.89	1.62	25.9	0.0000
								S6	Aspherical surface	28.6065	0.0550				0.0000
STO	Spherical surface	All-round	0.0539				0.0000
								S7	Aspherical surface	1.5265	0.4501	0.62	1.54	56.1	0.0000
S8	Aspherical surface	-0.3921	0.4055				-1.0000
								S9	Spherical surface	All-round	0.2100		1.52	64.2	0.0000
S10	Spherical surface	All-round	0.1962				0.0000
								S11	Spherical surface	All-round

Watch 10

As shown in table 11, in embodiment 4, the total effective focal length f of the optical imaging system is 0.35mm, the distance TTL on the optical axis from the object-side surface S3 of the first lens E2 to the imaging surface S11 is 2.56mm, the half ImgH of the diagonal line length of the effective pixel region on the imaging surface S11 is 1.02mm, and the half semifov of the maximum field angle of the optical imaging system is 78.36 °. The parameters of each relation are as explained in the first embodiment, and the values of each relation are as listed in the following table.

TABLE 11

In example 4, the object-side surface and the image-side surface of any one of the first lens E2 to the third lens E4 are aspheric, and table 12 shows the high-order term coefficients a that can be used for the aspheric mirror surfaces S3 to S8 in example 4₄、A₆、A₈、A₁₀、A₁₂、A₁₄、A₁₆、A₁₈、A₂₀、A₂₂、A₂₄、A₂₆、A₂₈And A₃₀。

Flour mark

A4

A6

A8

A10

A12

A14

A16

S3

-2.1114E-01

-1.0015E-01

-6.5041E-02

-3.5400E-02

-2.1768E-02

-1.3988E-02

-9.1021E-03

S4

3.9537E-01

-1.1045E-01

2.7888E-02

1.8296E-03

1.5072E-03

-2.9622E-03

5.3496E-04

S5

-1.2584E-01

5.6268E-03

-3.9671E-03

4.8832E-03

-1.2687E-03

1.5139E-03

-8.5685E-04

S6

5.9641E-02

-4.1349E-02

2.4665E-02

-1.2456E-02

7.1332E-03

-3.7436E-03

9.2115E-04

S7

-1.2713E-02

6.0588E-03

-1.7713E-03

7.5702E-04

-3.1996E-04

4.3473E-04

-1.1273E-04

S8

1.9982E-01

2.1425E-02

6.9982E-03

-5.6672E-03

7.6120E-04

1.3166E-05

1.3751E-03

Flour mark

A18

A20

A22

A24

A26

A28

A30

S3

-5.8536E-03

-3.8561E-03

-2.5175E-03

-1.6696E-03

-1.2721E-03

-6.9008E-04

-1.5244E-04

S4

4.9346E-04

1.4666E-03

-1.8335E-04

-1.2000E-03

-2.0379E-03

-1.2991E-03

-6.8762E-04

S5

4.6617E-04

-2.9030E-04

5.5657E-04

1.7961E-04

5.0428E-04

1.5837E-04

2.2395E-04

S6

3.6256E-04

-2.5493E-04

-4.1251E-05

-1.0502E-04

2.0125E-05

1.6626E-04

-2.1782E-04

S7

4.2842E-05

-2.1687E-04

-9.7667E-05

-1.2106E-04

-9.1585E-07

-1.1912E-05

3.6993E-05

S8

-8.6822E-04

-5.3443E-04

-7.3186E-04

-6.1421E-05

-3.3958E-04

-1.4395E-04

-2.2228E-04

TABLE 12

Fig. 8a shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 4, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 8b shows a distortion curve of the optical imaging system of embodiment 4, which represents distortion magnitude values corresponding to different image heights. Fig. 8c shows a chromatic aberration of magnification curve of the optical imaging system of embodiment 4, which represents the deviation of different image heights on the imaging plane after the light passes through the lens. As can be seen from fig. 8a to 8c, the optical imaging system according to embodiment 4 can achieve good imaging quality.

Specific example 5

Fig. 9 is a schematic view of a lens assembly structure according to embodiment 5 of the present invention, wherein the optical imaging system sequentially includes, from an object side to an image side along an optical axis: a glass screen E1, a first lens E2, a second lens E3, a stop STO, a third lens E4, a filter E5 and an image plane S11.

As shown in table 13, the basic parameter table of the optical imaging system of example 5 is shown, in which the units of the radius of curvature, the thickness, and the focal length are all millimeters (mm).

Flour mark	Surface type	Radius of curvature	Thickness/distance	Focal length	Refractive index	Coefficient of dispersion	Coefficient of cone
								OBJ	Spherical surface	All-round	0.0000
S1	Spherical surface	All-round	1.0000		1.52	64.2	0.0000
								S2	Spherical surface	All-round	1.2693				0.0000
S3	Aspherical surface	-0.5465	0.5129	-0.66	1.54	56.1	-1.0000
								S4	Aspherical surface	1.4159	0.2529				0.0000
S5	Aspherical surface	0.5305	0.3868	0.87	1.62	25.9	0.0000
								S6	Aspherical surface	46.4848	0.0592				-99.0000
STO	Spherical surface	All-round	0.0452				0.0000
								S7	Aspherical surface	1.4088	0.5000	0.60	1.54	56.1	0.0000
S8	Aspherical surface	-0.3703	0.3675				-1.0000
								S9	Spherical surface	All-round	0.2100		1.52	64.2	0.0000
S10	Spherical surface	All-round	0.1962				0.0000
								S11	Spherical surface	All-round

Watch 13

As shown in table 14, in embodiment 5, the total effective focal length f of the optical imaging system is 0.35mm, the distance TTL on the optical axis from the object-side surface S3 of the first lens E2 to the imaging surface S11 is 2.53mm, the half ImgH of the diagonal line length of the effective pixel region on the imaging surface S11 is 1.02mm, and the half semifov of the maximum field angle of the optical imaging system is 80.25 °. The parameters of each relation are as explained in the first embodiment, and the values of each relation are as listed in the following table.

TABLE 14

In example 5, the object-side surface and the image-side surface of any one of the first lens E2 to the third lens E4 are aspheric, and table 15 shows the high-order term coefficients a that can be used for the aspheric mirror surfaces S3 to S8 in example 5₄、A₆、A₈、A₁₀、A₁₂、A₁₄、A₁₆、A₁₈、A₂₀、A₂₂、A₂₄、A₂₆、A₂₈And A₃₀。

Flour mark

A4

A6

A8

A10

A12

A14

A16

S3

1.8303E+00

-4.1604E-01

1.3607E-01

-5.3727E-02

2.4047E-02

-1.1454E-02

5.7189E-03

S4

3.9393E-01

-1.1316E-01

3.2259E-02

5.4796E-03

1.1993E-03

-4.8101E-03

1.0536E-03

S5

-1.2773E-01

3.0533E-03

-5.7027E-03

5.5631E-03

-9.7191E-04

1.4986E-03

-1.0608E-03

S6

1.8509E-02

-4.6995E-03

-2.1080E-03

-1.2899E-03

-4.1717E-04

-4.7949E-04

-1.6843E-04

S7

-1.2977E-02

5.6157E-03

-1.6427E-03

8.3443E-04

-4.5715E-04

2.8962E-04

-1.7264E-04

S8

1.9671E-01

1.0922E-02

8.2152E-03

-3.7530E-03

8.7238E-04

-1.3828E-03

1.1247E-03

Flour mark

A18

A20

A22

A24

A26

A28

A30

S3

-2.9358E-03

1.5622E-03

-8.5234E-04

4.3551E-04

-2.4457E-04

1.1542E-04

-2.3037E-05

S4

1.5807E-03

1.6520E-03

-7.2067E-04

-1.4407E-03

-1.9244E-03

-9.8555E-04

-5.7069E-04

S5

3.6256E-04

-3.9603E-04

5.5542E-04

2.2003E-04

6.1944E-04

2.2726E-04

2.5898E-04

S6

-6.9290E-05

4.7026E-05

-1.9976E-05

4.6424E-06

6.5520E-06

3.5913E-05

2.3311E-06

S7

1.2924E-04

-7.9727E-05

4.2057E-05

-3.6317E-05

2.2073E-05

-2.7392E-05

1.4175E-05

S8

-1.4661E-04

1.2445E-04

-8.8663E-04

-6.5803E-04

-9.1727E-04

-4.4007E-04

-2.6684E-04

Watch 15

Fig. 10a shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 5, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 10b shows a distortion curve of the optical imaging system of embodiment 5, which represents distortion magnitude values corresponding to different image heights. Fig. 10c shows a chromatic aberration of magnification curve of the optical imaging system of embodiment 5, which represents the deviation of different image heights on the imaging plane after the light passes through the lens. As can be seen from fig. 10a to 10c, the optical imaging system according to embodiment 5 can achieve good imaging quality.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, improvements, equivalents, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

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

a first lens having a negative refractive power, an object side surface of which is a concave surface;

a second lens having a positive optical power;

a third lens having a positive optical power;

wherein the effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging lens satisfy: f/EPD < 1.6; the effective focal length f2 of the second lens and the effective focal length f1 of the first lens satisfy the following conditional expression:

|f2/f1|<1.4。

2. the optical imaging system of claim 1, wherein: the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the effective focal length f1 of the first lens satisfy: 2.0< | (f2+ f3)/f1| < 2.5.

3. The optical imaging system of claim 1, wherein: an effective focal length f3 of the third lens, a radius of curvature of the object-side surface of the third lens R5, and a radius of curvature of the image-side surface of the third lens R6 satisfy:

-1.6<f3/R5+f3/R6<-0.9。

4. the optical imaging system of claim 1, wherein: half of the Semi-FOV of the maximum field angle of the optical imaging system satisfies: Semi-FOV >70 deg.

5. The optical imaging system of claim 1, wherein: the central thickness CT3 of the third lens on the optical axis and the edge thickness ET3 of the third lens meet: 1.5< CT3/ET3< 2.1.

6. The optical imaging system of claim 1, wherein: the object height YO of the maximum imaging height of the optical imaging system and the half ImgH of the diagonal length of the effective pixel area on the imaging surface satisfy that: 4.0< YO/ImgH < 5.5.

7. The optical imaging system of claim 1, wherein: the on-axis distance TD from the object side surface of the first lens TO the image side surface of the last lens and the distance TO from the object TO the object side surface of the first lens on the optical axis satisfy that: 0.5< TD/TO < 1.0.

8. The optical imaging system of claim 1, wherein: the on-axis distance SL from the diaphragm to the imaging surface satisfies: 1.0mm < SL <1.5 mm.

9. The optical imaging system of claim 1, wherein: an on-axis distance SAG12 between the intersection point of the image side surface of the first lens and the optical axis and the effective radius vertex of the image side surface of the first lens and an air interval T12 between the first lens and the second lens on the optical axis satisfy that: 1.0< SAG12/T12< 1.5.

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

a second lens having an optical power;

a third lens with focal power, wherein the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface;

wherein the effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy the following conditional expression: 0.5< f2/f3< 1.7.

11. The optical imaging system of claim 10, wherein: the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the effective focal length f1 of the first lens satisfy: 2.0< | (f2+ f3)/f1| < 2.5.

12. The optical imaging system of claim 10, wherein: an effective focal length f3 of the third lens, a radius of curvature of the object-side surface of the third lens R5, and a radius of curvature of the image-side surface of the third lens R6 satisfy:

-1.6<f3/R5+f3/R6<-0.9。

13. the optical imaging system of claim 10, wherein: the central thickness CT3 of the third lens on the optical axis and the edge thickness ET3 of the third lens meet: 1.5< CT3/ET3< 2.1.

14. The optical imaging system of claim 10, wherein: half of the Semi-FOV of the maximum field angle of the optical imaging system satisfies: Semi-FOV >70 deg.

15. The optical imaging system of claim 10, wherein: the object height YO of the maximum imaging height of the optical imaging system and the half ImgH of the diagonal length of the effective pixel area on the imaging surface satisfy that: 4.0< YO/ImgH < 5.5.

16. The optical imaging system of claim 10, wherein: the on-axis distance TD from the object side surface of the first lens TO the image side surface of the last lens and the distance TO from the object TO the object side surface of the first lens on the optical axis satisfy that: 0.5< TD/TO < 1.0.

17. The optical imaging system of claim 10, wherein: the on-axis distance SL from the diaphragm to the imaging surface satisfies: 1.0mm < SL <1.5 mm.

18. The optical imaging system of claim 10, wherein: an on-axis distance SAG12 between the intersection point of the image side surface of the first lens and the optical axis and the effective radius vertex of the image side surface of the first lens and an air interval T12 between the first lens and the second lens on the optical axis satisfy that: 1.0< SAG12/T12< 1.5.

19. An identification module comprising the optical imaging system of any one of claims 1 to 18 and an electron-sensitive element disposed on an imaging surface of the optical imaging system.

20. An electronic device, characterized in that it comprises an identification module according to claim 19.