CN211905834U - Optical imaging system - Google Patents

Abstract

The application discloses an optical imaging system, which comprises in order from an object side to an image side along an optical axis: a first lens having an optical power; a second lens having a negative optical power; a third lens having a negative optical power; a fourth lens having a focal power, wherein the object-side surface of the fourth lens is convex, and the image-side surface of the fourth lens is concave; and a fifth lens having optical power. The distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging system on the optical axis and the half ImgH of the diagonal length of the effective pixel area on the imaging surface of the optical imaging system satisfy that: TTL/ImgH is more than 1.0 and less than 1.5.

Description

Optical imaging system

Technical Field

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

Background

With the progress of science and technology, portable electronic products such as smart phones and the like are rapidly developed. On the one hand, the imaging quality requirement of the user for photographing portable electronic products such as smart phones is continuously improved. On the other hand, users seek to make more and more thin portable electronic products such as smart phones and the like while pursuing higher pixel cameras, and the portable electronic products are convenient to carry. However, these two aspects tend to be conflicting in conventional lens designs, and lenses with high imaging quality typically have large dimensions.

Therefore, how to collect more light information with the total lens length as short as possible, keep smaller optical aberration and good imaging quality, reserve enough physical space for the module and the terminal complete machine, and facilitate the design of portable electronic products such as smart phones and the like is one of the problems that various large lens manufacturers need to solve urgently.

SUMMERY OF THE UTILITY MODEL

An aspect of the present application provides an optical imaging system, in order from an object side to an image side along an optical axis, comprising: a first lens having an optical power; a second lens having a negative optical power; a third lens having a negative optical power; a fourth lens having a focal power, wherein the object-side surface of the fourth lens is convex, and the image-side surface of the fourth lens is concave; and a fifth lens having optical power. The distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging system on the optical axis and the half of the diagonal length ImgH of the effective pixel area on the imaging surface of the optical imaging system can satisfy the following conditions: TTL/ImgH is more than 1.0 and less than 1.5.

In one embodiment, at least one of the object-side surface of the first lens to the image-side surface of the fifth lens may be an aspheric surface.

In one embodiment, a sum Σ AT of the distance between any adjacent two lenses of the first to fifth lenses on the optical axis and the distance T34 between the third lens and the fourth lens on the optical axis may satisfy: 5.5 < Sigma AT/T34 < 9.0.

In one embodiment, the total effective focal length f of the optical imaging system, the effective focal length f2 of the second lens, and the effective focal length f4 of the fourth lens may satisfy: -2.0 < f/(f2+ f4) < -0.5.

In one embodiment, a separation distance T12 on the optical axis of the first lens and the second lens, a separation distance T23 on the optical axis of the second lens and the third lens, and a separation distance T45 on the optical axis of the fourth lens and the fifth lens may satisfy: 1.5 < (T12+ T45)/T23 < 3.5.

In one embodiment, the effective focal length f4 of the fourth lens, the radius of curvature R8 of the image-side surface of the fourth lens, and the radius of curvature R10 of the image-side surface of the fifth lens may satisfy: 1.1 < f4/(| R8| + R10) < 2.0.

In one embodiment, the radius of curvature R2 of the image-side surface of the first lens, the radius of curvature R3 of the object-side surface of the second lens, the radius of curvature R4 of the image-side surface of the second lens, and the radius of curvature R6 of the image-side surface of the third lens may satisfy: 2.0 < (| R6| + R3)/(R2+ R4) < 5.0.

In one embodiment, the central thickness CT4 of the fourth lens on the optical axis and the separation distance T34 of the third lens and the fourth lens on the optical axis may satisfy: CT4/T34 is more than 3.0 and less than 6.5.

In one embodiment, the optical imaging system may satisfy: 1.0 < ETL/EIN < 1.5, wherein ETL is a distance parallel to the optical axis between a position of an object-side surface of the first lens at an 1/2 entrance pupil diameter of the optical imaging system and an imaging plane of the optical imaging system, and EIN is a distance parallel to the optical axis between a position of an object-side surface of the first lens at an 1/2 entrance pupil diameter of the optical imaging system and a position of an image-side surface of the fifth lens at an 1/2 entrance pupil diameter of the optical imaging system.

In one embodiment, the edge thickness ET5 of the fifth lens and the edge thickness ET1 of the first lens may satisfy: 1.0 < ET5/ET1 < 3.5.

In one embodiment, the combined focal length f23 of the second and third lenses and the effective focal length f5 of the fifth lens may satisfy: f23/f5 is more than 1.0 and less than 2.0.

In one embodiment, the central thickness CT4 of the fourth lens on the optical axis and the edge thickness ET4 of the fourth lens can satisfy: 1.5 < CT4/ET4 < 2.0.

In one embodiment, the combined focal length f12 of the first and second lenses and the total effective focal length f of the optical imaging system may satisfy: f12/f is more than 1.0 and less than 1.5.

In one embodiment, the maximum effective radius DT11 of the object-side surface of the first lens, the maximum effective radius DT21 of the object-side surface of the second lens, and the maximum effective radius DT51 of the object-side surface of the fifth lens may satisfy: 1.5 < DT51/(DT11+ DT21) < 2.0.

In one embodiment, the central thickness CT5 of the fifth lens on the optical axis and the central thickness CT3 of the third lens on the optical axis may satisfy: 1.5 < CT5/CT3 < 3.5.

Another aspect of the present application provides an optical imaging system, in order from an object side to an image side along an optical axis, comprising: a first lens having an optical power; a second lens having a negative optical power; a third lens having a negative optical power; a fourth lens having an optical power; and a fifth lens having optical power. A distance ETL parallel to the optical axis of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system to the imaging plane of the optical imaging system and a distance EIN parallel to the optical axis of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system to the image-side surface of the fifth lens at the 1/2 entrance pupil diameter of the optical imaging system may satisfy: ETL/EIN is more than 1.0 and less than 1.5.

In one embodiment, the object-side surface of the fourth lens element can be convex and the image-side surface can be concave.

The optical imaging system adopts a plurality of lenses (for example, five lenses), and has at least one beneficial effect of ultrathin and good imaging quality and the like 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.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

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

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

fig. 3 shows a schematic configuration diagram of an optical imaging system according to embodiment 2 of the present application;

fig. 4A to 4D show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a chromatic aberration of magnification curve, respectively, of the optical imaging system of embodiment 2;

fig. 5 shows a schematic configuration diagram of an optical imaging system according to embodiment 3 of the present application;

fig. 6A to 6D show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a chromatic aberration of magnification curve, respectively, of the optical imaging system of embodiment 3;

fig. 7 shows a schematic configuration diagram of an optical imaging system according to embodiment 4 of the present application;

fig. 8A to 8D show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a chromatic aberration of magnification curve, respectively, of the optical imaging system of embodiment 4;

fig. 9 shows a schematic configuration diagram of an optical imaging system according to embodiment 5 of the present application;

fig. 10A to 10D show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a chromatic aberration of magnification curve, respectively, of the optical imaging system of embodiment 5;

fig. 11 shows a schematic configuration diagram of an optical imaging system according to embodiment 6 of the present application; and

fig. 12A to 12D show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a chromatic aberration of magnification curve, respectively, of the optical imaging system of embodiment 6.

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 five lenses having optical powers, which are a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, respectively. The five lenses are arranged along the optical axis in sequence from the object side to the image side. Any adjacent two lenses of the first lens to the fifth lens can have a spacing distance therebetween.

In an exemplary embodiment, the first lens may have a positive power or a negative power; the second lens may have a negative optical power; the third lens may have a negative optical power; the fourth lens can have positive focal power or negative focal power, and the object side surface of the fourth lens can be a convex surface, and the image side surface of the fourth lens can be a concave surface; the fifth lens may have a positive power or a negative power.

The second lens has negative focal power, so that the light rays can be diffused outwards, the system has a larger field angle, and the chief ray angle of a high-pixel chip can be matched. The third lens has negative focal power, can adjust optical magnification, corrects aberration caused by the front two lenses, further diverges light rays, and is favorable for realizing an optical system with a small aperture and a large image plane.

In an exemplary embodiment, the object-side surface of the fourth lens element may be convex and the image-side surface may be concave. The convex-concave design of the fourth lens is beneficial to the fourth lens to better converge light, balance various large aberration, facilitate mechanism typesetting and reduce the structural sensitivity.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.0 < TTL/Imgh < 1.5, wherein TTL is the distance between the object side surface of the first lens and the imaging surface of the optical imaging system on the optical axis, and Imgh is half of the length of the diagonal line of the effective pixel area on the imaging surface of the optical imaging system. More specifically, TTL and ImgH may further satisfy: TTL/ImgH is more than 1.2 and less than 1.5. The requirements that TTL/ImgH is more than 1.0 and less than 1.5 are met, the total length of the lens can be reduced as far as possible while a larger image plane is ensured, and the purpose of ultra-thinness is achieved.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 5.5 < Σ AT/T34 < 9.0, where Σ AT is the sum of the separation distances on the optical axis of any adjacent two lenses of the first to fifth lenses, and T34 is the separation distance on the optical axis of the third and fourth lenses. More specifically, Σ AT and T34 may further satisfy: 5.6 < Sigma AT/T34 < 8.9. The requirement that ∑ AT/T34 is more than 5.5 and less than 9.0 is met, the sensitivity of the spacing distance between two adjacent lenses is balanced, excessive concentration of the sensitivity is avoided, the spacing distance of the third lens and the fourth lens on the optical axis is controlled, the third lens and the fourth lens are enabled to be closer, and structural typesetting is facilitated.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: -2.0 < f/(f2+ f4) < -0.5, wherein f is the total effective focal length of the optical imaging system, f2 is the effective focal length of the second lens, and f4 is the effective focal length of the fourth lens. More specifically, f2, and f4 may further satisfy: -1.6 < f/(f2+ f4) < -0.9. Satisfies-2.0 < f/(f2+ f4) < -0.5, can reduce the deflection angle of light and reduce the sensitivity of the system.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.5 < (T12+ T45)/T23 < 3.5, wherein T12 is a distance between the first lens and the second lens on the optical axis, T23 is a distance between the second lens and the third lens on the optical axis, and T45 is a distance between the fourth lens and the fifth lens on the optical axis. More specifically, T12, T45, and T23 may further satisfy: 1.5 < (T12+ T45)/T23 < 3.2. Satisfying 1.5 < (T12+ T45)/T23 < 3.5 can make the optical system have better capability of balancing dispersion, and the close distance of the three intervals is beneficial to reducing the assembly sensitivity of the system and facilitating the assembly production.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.1 < f4/(| R8| + R10) < 2.0, wherein f4 is an effective focal length of the fourth lens, R8 is a radius of curvature of an image-side surface of the fourth lens, and R10 is a radius of curvature of an image-side surface of the fifth lens. More specifically, f4, R8, and R10 may further satisfy: 1.1 < f4/(| R8| + R10) < 1.6. The optical lens meets the requirement that f4/(| R8| + R10) < 2.0 < 1.1, the off-axis chromatic aberration of an optical system can be reduced, the total effective focal length of the lens can be effectively increased, the focal power of the fourth lens is reasonably distributed, the sensitivity of actual part processing can be reduced, and the production yield of the lens can be improved.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 2.0 < (| R6| + R3)/(R2+ R4) < 5.0, wherein R2 is the radius of curvature of the image-side surface of the first lens, R3 is the radius of curvature of the object-side surface of the second lens, R4 is the radius of curvature of the image-side surface of the second lens, and R6 is the radius of curvature of the image-side surface of the third lens. More specifically, R6, R3, R2 and R4 may further satisfy: 2.3 < (| R6| + R3)/(R2+ R4) < 4.8. Satisfy 2.0 < (| R6| + R3)/(R2+ R4) < 5.0, can make optical system can better match the chief ray angle of chip, be favorable to optical system to balance field curvature and distortion more easily.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 3.0 < CT4/T34 < 6.5, wherein CT4 is the central thickness of the fourth lens on the optical axis, and T34 is the separation distance between the third lens and the fourth lens on the optical axis. The requirements of CT4/T34 being more than 3.0 and less than 6.5 are met, the processing manufacturability of the third lens and the fourth lens can be effectively ensured, the forming characteristic of the plastic lens is more facilitated, and the production and the assembly are stable.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.0 < ETL/EIN < 1.5, wherein ETL is the distance parallel to the optical axis from the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system to the imaging plane of the optical imaging system, and EIN is the distance parallel to the optical axis from the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system to the image-side surface of the fifth lens at the 1/2 entrance pupil diameter of the optical imaging system. More specifically, ETL and EIN may further satisfy: ETL/EIN is more than 1.1 and less than 1.3. ETL/EIN is more than 1.0 and less than 1.5, so that the total length of the optical system is favorably reduced, and the angle of a main ray of the optical system is controlled, thereby being favorable for matching chips.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.0 < ET5/ET1 < 3.5, wherein ET5 is the edge thickness of the fifth lens and ET1 is the edge thickness of the first lens. More specifically, ET5 and ET1 further satisfy: 1.1 < ET5/ET1 < 3.3. The method meets the conditions that ET5/ET1 is more than 1.0 and less than 3.5, can ensure that the edge thickness of the lens can meet the actual processing requirement, and is beneficial to increasing the relative brightness of the edge field and converging the chromatic aberration of the edge field.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.0 < f23/f5 < 2.0, wherein f23 is the combined focal length of the second lens and the third lens, and f5 is the effective focal length of the fifth lens. More specifically, f23 and f5 may further satisfy: f23/f5 is more than 1.4 and less than 1.9. Satisfying 1.0 < f23/f5 < 2.0, can effectively reduce the distortion of the edge of the optical system, is beneficial to ensuring the relative brightness of the edge field of view, and ensures that the optical system has better imaging effect.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.5 < CT4/ET4 < 2.0, wherein CT4 is the central thickness of the fourth lens on the optical axis and ET4 is the edge thickness of the fourth lens. More specifically, CT4 and ET4 further satisfy: 1.5 < CT4/ET4 < 1.9. The thickness ratio of the fourth lens can be indirectly controlled to ensure that the fourth lens meets the forming requirement and the occurrence of weld marks is avoided, wherein CT4/ET4 is more than 1.5 and less than 2.0.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.0 < f12/f < 1.5, wherein f12 is the combined focal length of the first lens and the second lens, and f is the total effective focal length of the optical imaging system. More specifically, f12 and f further satisfy: f12/f is more than 1.0 and less than 1.3. Satisfying 1.0 < f12/f < 1.5, the optical system has better ability of balancing field curvature, and better image quality.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.5 < DT51/(DT11+ DT21) < 2.0, where DT11 is the maximum effective radius of the object-side face of the first lens, DT21 is the maximum effective radius of the object-side face of the second lens, and DT51 is the maximum effective radius of the object-side face of the fifth lens. The zoom lens meets DT51/(DT11+ DT21) < 2.0 < 1.5, is beneficial to ensuring that the lens has a longer focal length, properly controls the depth of field range, and is beneficial to meeting the shooting requirements of more people.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.5 < CT5/CT3 < 3.5, wherein CT5 is the central thickness of the fifth lens on the optical axis, and CT3 is the central thickness of the third lens on the optical axis. More specifically, CT5 and CT3 further satisfy: 1.6 < CT5/CT3 < 3.3. The requirements of 1.5 < CT5/CT3 < 3.5 are met, so that the lens can better meet the process molding requirements, and the occurrence of weld marks is avoided.

In an exemplary embodiment, the optical imaging system according to the present application further includes a stop 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-described embodiment of the present application may employ a plurality of lenses, for example, five lenses as described above. 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 incident light can be effectively converged, the total length of the optical imaging system is reduced, the processability of the optical imaging system is improved, the structure of each lens is more compact, the optical imaging system is more beneficial to production and processing, and the practicability is higher. With the above configuration, the optical imaging system according to the exemplary embodiment of the present application can have characteristics such as ultra-thinness, small aberration, good imaging quality, and the like.

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.

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 2D. Fig. 1 shows a schematic configuration diagram of an optical imaging system according to embodiment 1 of the present application.

As shown in fig. 1, the optical imaging system, in order from an object side to an image side, comprises: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an image forming surface S13.

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

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 the present example, the total effective focal length f of the optical imaging system is 3.79mm, the total length TTL of the optical imaging system (i.e., the distance on the optical axis from the object-side surface S1 of the first lens E1 to the imaging surface S13 of the optical imaging system) is 4.62mm, the half ImgH of the diagonal length of the effective pixel area on the imaging surface S13 of the optical imaging system is 3.28mm, the maximum half field angle Semi-FOV of the optical imaging system is 40.0 °, the aperture value Fno of the optical imaging system is 2.48, the distance ETL parallel to the optical axis between the position of the object-side surface of the first lens at the entrance pupil diameter 1/2 of the optical imaging system and the imaging surface of the optical imaging system is 4.37mm, and a distance EIN parallel to the optical axis between a position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and a position of the image-side surface of the fifth lens at the 1/2 entrance pupil diameter of the optical imaging system is 3.67 mm.

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 coefficient A of each of the aspherical mirror surfaces S1 to S10 used in example 1₄、A₆、A₈、A₁₀、A₁₂、A₁₄、A₁₆、A₁₈And A₂₀。

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

2.8562E-02

7.3677E-02

-3.4351E-01

1.4804E+00

-3.3245E+00

3.4085E+00

1.0575E+00

-5.4088E+00

3.4553E+00

S2

-3.4969E-02

5.5903E-02

-6.1699E-01

4.7674E+00

-2.1678E+01

5.8324E+01

-9.1958E+01

7.9041E+01

-2.9208E+01

S3

-2.8300E-02

4.4629E-02

7.1465E-01

-5.9370E+00

3.0224E+01

-9.7504E+01

1.9165E+02

-2.0751E+02

9.4573E+01

S4

-1.5793E-02

2.4351E-01

-1.4671E+00

1.0254E+01

-4.6154E+01

1.3336E+02

-2.3782E+02

2.3904E+02

-1.0331E+02

S5

-3.2973E-01

2.5669E-01

-1.7842E+00

8.6692E+00

-2.7582E+01

5.4980E+01

-6.5593E+01

4.3556E+01

-1.2608E+01

S6

-3.2986E-01

2.6454E-01

-8.4324E-01

2.5536E+00

-4.9433E+00

6.2869E+00

-4.8082E+00

1.9914E+00

-3.4779E-01

S7

-1.0540E-01

1.2507E-01

-3.4126E-01

9.6942E-01

-1.3744E+00

1.0757E+00

-4.8455E-01

1.1863E-01

-1.2290E-02

S8

-2.3739E-01

3.2929E-01

-3.7793E-01

3.5997E-01

-2.2530E-01

8.7411E-02

-2.0449E-02

2.6567E-03

-1.4776E-04

S9

-2.7847E-01

1.7643E-01

-6.8546E-02

2.0067E-02

-4.3777E-03

6.6776E-04

-6.6047E-05

3.7774E-06

-9.4601E-08

S10

-1.0493E-01

5.8143E-02

-2.3339E-02

6.6077E-03

-1.3135E-03

1.7662E-04

-1.5176E-05

7.5278E-07

-1.6438E-08

TABLE 2

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 an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of embodiment 1. Fig. 2C shows a distortion curve of the optical imaging system of embodiment 1, which represents distortion magnitude values corresponding to different image heights. Fig. 2D shows a chromatic aberration of magnification curve of the optical imaging system of embodiment 1, which represents a deviation of different image heights on the imaging plane after the light passes through the lens. As can be seen from fig. 2A to 2D, the optical imaging system according to embodiment 1 can achieve good imaging quality.

Example 2

An optical imaging system according to embodiment 2 of the present application is described below with reference to fig. 3 to 4D. In this embodiment and the following embodiments, descriptions of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 3 shows a schematic structural diagram of an optical imaging system according to embodiment 2 of the present application.

As shown in fig. 3, the optical imaging system, in order from an object side to an image side, comprises: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an image forming surface S13.

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

In the present example, the total effective focal length f of the optical imaging system is 3.79mm, the total length TTL of the optical imaging system is 4.59mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S13 of the optical imaging system is 3.28mm, the maximum half field angle Semi-FOV of the optical imaging system is 40.0 °, the aperture value Fno of the optical imaging system is 2.48, the distance ETL parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the imaging plane of the optical imaging system is 4.34mm, and the distance EIN parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the position of the image-side surface of the fifth lens at the 1/2 entrance pupil diameter of the optical imaging system is 3.64 mm.

Table 3 shows a basic parameter table of the optical imaging system of example 2, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 4 shows high-order term coefficients that can be used for each aspherical mirror surface in example 2, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 3

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

2.8350E-02

8.1588E-02

-4.2953E-01

2.0512E+00

-5.6115E+00

9.0788E+00

-7.3953E+00

1.5203E+00

1.0668E+00

S2

-3.7762E-02

9.3387E-02

-1.1119E+00

8.7890E+00

-4.1772E+01

1.2039E+02

-2.0774E+02

1.9851E+02

-8.1752E+01

S3

-3.4596E-02

5.9335E-02

6.8331E-01

-5.9153E+00

3.0855E+01

-1.0141E+02

2.0202E+02

-2.2108E+02

1.0173E+02

S4

-2.1264E-02

2.4845E-01

-1.4349E+00

1.0274E+01

-4.7778E+01

1.4315E+02

-2.6500E+02

2.7626E+02

-1.2354E+02

S5

-2.9515E-01

2.3537E-01

-1.7158E+00

8.8501E+00

-2.9059E+01

5.9712E+01

-7.3747E+01

5.0600E+01

-1.5031E+01

S6

-3.0239E-01

2.3122E-01

-6.8215E-01

2.0597E+00

-3.7466E+00

4.4670E+00

-3.2773E+00

1.3276E+00

-2.3017E-01

S7

-1.2149E-01

1.4538E-01

-4.4869E-01

1.2541E+00

-1.7526E+00

1.3602E+00

-6.0899E-01

1.4838E-01

-1.5315E-02

S8

-2.5476E-01

3.7283E-01

-4.6247E-01

4.5647E-01

-2.9002E-01

1.1340E-01

-2.6631E-02

3.4633E-03

-1.9240E-04

S9

-2.4681E-01

1.3559E-01

-3.9311E-02

7.4854E-03

-9.9595E-04

9.3406E-05

-5.9474E-06

2.3116E-07

-4.1202E-09

S10

-9.2447E-02

4.3305E-02

-1.4172E-02

3.0831E-03

-4.3597E-04

3.6164E-05

-1.2632E-06

-2.1438E-08

2.0140E-09

TABLE 4

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 an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of embodiment 2. Fig. 4C shows a distortion curve of the optical imaging system of embodiment 2, which represents distortion magnitude values corresponding to different image heights. Fig. 4D 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 4D, the optical imaging system according to embodiment 2 can achieve good imaging quality.

Example 3

An optical imaging system according to embodiment 3 of the present application is described below with reference to fig. 5 to 6D. Fig. 5 shows a schematic structural diagram of an optical imaging system according to embodiment 3 of the present application.

As shown in fig. 5, the optical imaging system, in order from an object side to an image side, comprises: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an image forming surface S13.

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

In the present example, the total effective focal length f of the optical imaging system is 3.60mm, the total length TTL of the optical imaging system is 4.24mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S13 of the optical imaging system is 3.38mm, the maximum half field angle Semi-FOV of the optical imaging system is 42.3 °, the aperture value Fno of the optical imaging system is 2.48, the distance ETL parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the imaging plane of the optical imaging system is 4.00mm, and the distance EIN parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the position of the image-side surface of the fifth lens at the 1/2 entrance pupil diameter of the optical imaging system is 3.43 mm.

Table 5 shows a basic parameter table of the optical imaging system of example 3, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 6 shows high-order term coefficients that can be used for each aspherical mirror surface in example 3, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 5

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

2.5648E-02

1.7821E-01

-1.5898E+00

1.0534E+01

-4.3213E+01

1.1165E+02

-1.7462E+02

1.5048E+02

-5.4436E+01

S2

-6.8652E-02

1.3085E-01

-1.6568E+00

1.3690E+01

-6.9043E+01

2.1137E+02

-3.9122E+02

4.0574E+02

-1.8502E+02

S3

-4.9961E-02

-5.3206E-02

2.9097E+00

-2.4149E+01

1.2361E+02

-4.0049E+02

7.9173E+02

-8.6863E+02

4.0455E+02

S4

-4.6656E-02

4.2545E-01

-3.1236E+00

2.2817E+01

-1.0598E+02

3.1184E+02

-5.6307E+02

5.7098E+02

-2.4871E+02

S5

-3.5582E-01

3.9742E-01

-2.9739E+00

1.5726E+01

-5.4461E+01

1.1814E+02

-1.5347E+02

1.1086E+02

-3.4736E+01

S6

-3.5876E-01

4.5410E-01

-1.8556E+00

6.2015E+00

-1.3717E+01

1.9767E+01

-1.7293E+01

8.3846E+00

-1.7537E+00

S7

-1.4050E-01

2.0987E-01

-4.6610E-01

1.1846E+00

-1.6243E+00

1.2387E+00

-5.4200E-01

1.2848E-01

-1.2868E-02

S8

-3.3061E-01

5.9804E-01

-9.2921E-01

1.1542E+00

-9.1299E-01

4.4132E-01

-1.2769E-01

2.0443E-02

-1.3994E-03

S9

-3.2467E-01

2.2205E-01

-9.3137E-02

2.7402E-02

-5.5946E-03

7.6708E-04

-6.7075E-05

3.3758E-06

-7.4438E-08

S10

-1.2747E-01

7.8349E-02

-3.4325E-02

1.0628E-02

-2.3049E-03

3.3478E-04

-3.0611E-05

1.5861E-06

-3.5475E-08

TABLE 6

Fig. 6A shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 3, which represents the convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 6B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of embodiment 3. Fig. 6C shows a distortion curve of the optical imaging system of embodiment 3, which represents distortion magnitude values corresponding to different image heights. Fig. 6D 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 6D, the optical imaging system according to embodiment 3 can achieve good imaging quality.

Example 4

An optical imaging system according to embodiment 4 of the present application is described below with reference to fig. 7 to 8D. Fig. 7 shows a schematic structural diagram of an optical imaging system according to embodiment 4 of the present application.

As shown in fig. 7, the optical imaging system, in order from an object side to an image side, comprises: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an image forming surface S13.

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

In the present example, the total effective focal length f of the optical imaging system is 3.86mm, the total length TTL of the optical imaging system is 4.60mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S13 of the optical imaging system is 3.38mm, the maximum half field angle Semi-FOV of the optical imaging system is 40.3 °, the aperture value Fno of the optical imaging system is 2.48, the distance ETL parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the imaging plane of the optical imaging system is 4.34mm, and the distance EIN parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the position of the image-side surface of the fifth lens at the 1/2 entrance pupil diameter of the optical imaging system is 3.52 mm.

Table 7 shows a basic parameter table of the optical imaging system of example 4 in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm). Table 8 shows high-order term coefficients that can be used for each aspherical mirror surface in example 4, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 7

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

2.7338E-02

8.5019E-02

-5.2591E-01

3.0417E+00

-1.0902E+01

2.5014E+01

-3.4789E+01

2.6651E+01

-8.4972E+00

S2

-4.1795E-02

4.9969E-02

-2.7055E-01

1.8164E+00

-6.9222E+00

1.4227E+01

-1.3441E+01

1.9472E+00

3.5296E+00

S3

-6.4154E-02

1.4886E-01

-2.1928E-01

1.7353E+00

-8.4730E+00

2.1902E+01

-2.9963E+01

1.9298E+01

-3.7244E+00

S4

-5.9532E-02

2.2118E-01

-5.3412E-01

2.6838E+00

-8.9760E+00

1.8895E+01

-2.3701E+01

1.6590E+01

-4.9659E+00

S5

-3.1049E-01

7.9269E-02

-1.1228E+00

6.4698E+00

-2.1312E+01

4.1548E+01

-4.6345E+01

2.7690E+01

-6.9887E+00

S6

-2.8402E-01

8.1524E-02

-5.0381E-01

2.3135E+00

-5.6832E+00

8.4323E+00

-7.1681E+00

3.2298E+00

-6.0533E-01

S7

-6.9039E-02

3.7227E-02

-1.0997E-01

3.6665E-01

-4.6128E-01

2.9885E-01

-1.0848E-01

2.1100E-02

-1.7217E-03

S8

-1.9218E-01

2.5136E-01

-2.7968E-01

2.6598E-01

-1.6092E-01

5.8786E-02

-1.2744E-02

1.5189E-03

-7.6971E-05

S9

-3.0808E-01

2.1550E-01

-9.3558E-02

2.8736E-02

-6.1432E-03

8.8223E-04

-8.0790E-05

4.2585E-06

-9.8375E-08

S10

-1.2682E-01

7.5782E-02

-3.2864E-02

9.9858E-03

-2.1376E-03

3.1319E-04

-2.9765E-05

1.6493E-06

-4.0254E-08

TABLE 8

Fig. 8A shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 4, which represents the convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 8B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of embodiment 4. Fig. 8C shows a distortion curve of the optical imaging system of embodiment 4, which represents distortion magnitude values corresponding to different image heights. Fig. 8D 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 8D, the optical imaging system according to embodiment 4 can achieve good imaging quality.

Example 5

An optical imaging system according to embodiment 5 of the present application is described below with reference to fig. 9 to 10D. Fig. 9 shows a schematic structural diagram of an optical imaging system according to embodiment 5 of the present application.

As shown in fig. 9, the optical imaging system, in order from an object side to an image side, comprises: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an image forming surface S13.

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

In the present example, the total effective focal length f of the optical imaging system is 3.82mm, the total length TTL of the optical imaging system is 4.65mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S13 of the optical imaging system is 3.28mm, the maximum half field angle Semi-FOV of the optical imaging system is 39.8 °, the aperture value Fno of the optical imaging system is 2.48, the distance ETL parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the imaging plane of the optical imaging system is 4.41mm, and the distance EIN parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the position of the image-side surface of the fifth lens at the 1/2 entrance pupil diameter of the optical imaging system is 3.63 mm.

Table 9 shows a basic parameter table of the optical imaging system of example 5 in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm). Table 10 shows high-order term coefficients that can be used for each aspherical mirror surface in example 5, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 9

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

2.4144E-02

1.0370E-01

-7.4757E-01

4.4791E+00

-1.6492E+01

3.8411E+01

-5.4139E+01

4.2123E+01

-1.3753E+01

S2

-4.5268E-02

7.4807E-02

-7.1602E-01

5.6451E+00

-2.6045E+01

7.1538E+01

-1.1529E+02

1.0087E+02

-3.7033E+01

S3

-6.6831E-02

1.6263E-01

-6.5451E-01

5.3163E+00

-2.5338E+01

6.9999E+01

-1.1207E+02

9.6485E+01

-3.4528E+01

S4

-7.1419E-02

3.2049E-01

-1.6251E+00

9.3303E+00

-3.3697E+01

7.5523E+01

-1.0154E+02

7.4932E+01

-2.3205E+01

S5

-3.1093E-01

1.3082E-01

-5.9200E-01

2.8795E+00

-8.7865E+00

1.5777E+01

-1.5848E+01

8.4207E+00

-1.8930E+00

S6

-3.0494E-01

1.3556E-01

-2.3552E-01

7.8402E-01

-1.7256E+00

2.2880E+00

-1.6278E+00

5.7234E-01

-7.8544E-02

S7

-5.3419E-02

-8.9458E-03

3.7463E-02

2.0358E-02

-5.1279E-02

3.2599E-02

-1.0232E-02

1.6414E-03

-1.0790E-04

S8

-1.2659E-01

1.3569E-01

-1.3160E-01

1.1483E-01

-6.1779E-02

1.9614E-02

-3.6480E-03

3.7002E-04

-1.5867E-05

S9

-3.4653E-01

2.3347E-01

-9.4258E-02

2.6598E-02

-5.2527E-03

7.0416E-04

-6.0749E-05

3.0365E-06

-6.6798E-08

S10

-1.4129E-01

8.6601E-02

-3.6876E-02

1.0905E-02

-2.2454E-03

3.1344E-04

-2.8183E-05

1.4699E-06

-3.3661E-08

Watch 10

Fig. 10A shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 5, which represents the convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 10B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of example 5. Fig. 10C shows a distortion curve of the optical imaging system of embodiment 5, which represents distortion magnitude values corresponding to different image heights. Fig. 10D 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 10D, the optical imaging system according to embodiment 5 can achieve good imaging quality.

Example 6

An optical imaging system according to embodiment 6 of the present application is described below with reference to fig. 11 to 12D. Fig. 11 shows a schematic configuration diagram of an optical imaging system according to embodiment 6 of the present application.

As shown in fig. 11, the optical imaging system, in order from an object side to an image side, comprises: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an image forming surface S13.

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

In the present example, the total effective focal length f of the optical imaging system is 3.77mm, the total length TTL of the optical imaging system is 4.35mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S13 of the optical imaging system is 3.28mm, the maximum half field angle Semi-FOV of the optical imaging system is 40.3 °, the aperture value Fno of the optical imaging system is 2.48, the distance ETL parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the imaging plane of the optical imaging system is 4.11mm, and the distance EIN parallel to the optical axis between the position of the object-side surface of the first lens at the 1/2 entrance pupil diameter of the optical imaging system and the position of the image-side surface of the fifth lens at the 1/2 entrance pupil diameter of the optical imaging system is 3.33 mm.

Table 11 shows a basic parameter table of the optical imaging system of example 6 in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm). Table 12 shows high-order term coefficients that can be used for each aspherical mirror surface in example 6, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 11

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

1.1705E-02

2.6105E-01

-2.5347E+00

1.5082E+01

-5.6484E+01

1.3342E+02

-1.9345E+02

1.5712E+02

-5.4835E+01

S2

-1.7549E-01

-6.8707E-01

1.4038E+01

-9.4934E+01

3.5697E+02

-8.2221E+02

1.1595E+03

-9.2751E+02

3.2422E+02

S3

-1.0686E-01

-5.1282E-01

1.2525E+01

-8.2055E+01

2.9439E+02

-6.3993E+02

8.4618E+02

-6.3396E+02

2.0853E+02

S4

-6.9893E-02

1.2900E+00

-1.2622E+01

8.8669E+01

-3.8810E+02

1.0457E+03

-1.6824E+03

1.4823E+03

-5.5045E+02

S5

-3.5217E-01

1.4603E+00

-1.4011E+01

9.1055E+01

-3.6834E+02

9.2077E+02

-1.3869E+03

1.1561E+03

-4.1004E+02

S6

-3.1329E-01

2.2143E-01

4.6401E-01

-2.5032E+00

7.1749E+00

-1.3147E+01

1.4328E+01

-8.2274E+00

1.8973E+00

S7

-2.0362E-01

-1.9648E-01

1.5122E+00

-3.3972E+00

6.0160E+00

-8.0948E+00

6.8062E+00

-3.0760E+00

5.6837E-01

S8

-4.6012E-01

8.7619E-01

-1.4785E+00

1.9112E+00

-1.5031E+00

6.8157E-01

-1.6809E-01

1.8730E-02

-4.0577E-04

S9

-3.8657E-01

3.3067E-01

-1.8184E-01

7.3149E-02

-2.0533E-02

3.8217E-03

-4.4649E-04

2.9599E-05

-8.4896E-07

S10

-1.6221E-01

1.0956E-01

-5.1806E-02

1.6331E-02

-3.3915E-03

4.4123E-04

-3.2219E-05

9.9463E-07

7.6927E-10

TABLE 12

Fig. 12A shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 6, which represents the convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 12B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of example 6. Fig. 12C shows a distortion curve of the optical imaging system of embodiment 6, which represents distortion magnitude values corresponding to different image heights. Fig. 12D shows a chromatic aberration of magnification curve of the optical imaging system of embodiment 6, which represents a deviation of different image heights on the imaging plane after the light passes through the lens. As can be seen from fig. 12A to 12D, the optical imaging system according to embodiment 6 can achieve good imaging quality.

In summary, examples 1 to 6 each satisfy the relationship shown in table 13.

Conditions/examples	1	2	3	4	5	6
							TTL/ImgH	1.41	1.40	1.25	1.36	1.42	1.32
ΣAL/T34	8.49	8.09	8.81	5.64	5.72	7.62
							f/(f2+f4)	-1.33	-1.52	-1.44	-1.43	-0.97	-1.03
(T12+T45)/T23	1.69	1.82	3.15	1.62	1.56	2.61
							f4/(|R8|+R10)	1.29	1.36	1.58	1.40	1.15	1.30
(|R6|+R3)/(R2+R4)	2.40	3.24	3.33	4.76	2.65	3.47
							CT4/T34	6.45	5.51	3.18	3.26	3.60	3.83
ETL/EIN	1.19	1.19	1.17	1.23	1.21	1.23
							ET5/ET1	3.28	2.96	2.32	1.83	2.44	1.16
f23/f5	1.54	1.45	1.73	1.84	1.84	1.76
							CT4/ET4	1.55	1.63	1.80	1.66	1.81	1.75
f12/f	1.13	1.12	1.21	1.18	1.26	1.01
							DT51/(DT11+DT21)	1.67	1.79	1.95	1.78	1.64	1.56
CT5/CT3	3.29	2.84	1.93	2.60	2.14	1.61

Watch 13

The present application also provides an imaging device whose electron photosensitive element may be a photo-coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging 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 the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims (28)

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

a first lens having an optical power;

a second lens having a negative optical power;

a third lens having a negative optical power;

a fourth lens having a focal power, wherein the object-side surface of the fourth lens is convex, and the image-side surface of the fourth lens is concave; and

a fifth lens having optical power;

the distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging system on the optical axis and the half ImgH of the diagonal length of the effective pixel area on the imaging surface of the optical imaging system satisfy that: TTL/ImgH is more than 1.0 and less than 1.5.

2. The optical imaging system according to claim 1, wherein a sum Σ AT of separation distances on the optical axis of any adjacent two lenses of the first to fifth lenses and a separation distance T34 on the optical axis of the third and fourth lenses satisfies: 5.5 < Sigma AT/T34 < 9.0.

3. The optical imaging system of claim 1, wherein the total effective focal length f of the optical imaging system, the effective focal length f2 of the second lens, and the effective focal length f4 of the fourth lens satisfy: -2.0 < f/(f2+ f4) < -0.5.

4. The optical imaging system according to claim 1, wherein a separation distance T12 on the optical axis of the first lens and the second lens, a separation distance T23 on the optical axis of the second lens and the third lens, and a separation distance T45 on the optical axis of the fourth lens and the fifth lens satisfy: 1.5 < (T12+ T45)/T23 < 3.5.

5. The optical imaging system of claim 1, wherein an effective focal length f4 of the fourth lens, a radius of curvature R8 of an image-side surface of the fourth lens, and a radius of curvature R10 of an image-side surface of the fifth lens satisfy: 1.1 < f4/(| R8| + R10) < 2.0.

6. The optical imaging system of claim 1, wherein the radius of curvature of the image-side surface of the first lens, R2, the radius of curvature of the object-side surface of the second lens, R3, the radius of curvature of the image-side surface of the second lens, R4, and the radius of curvature of the image-side surface of the third lens, R6 satisfy: 2.0 < (| R6| + R3)/(R2+ R4) < 5.0.

7. The optical imaging system of claim 1, wherein a center thickness CT4 of the fourth lens on the optical axis is separated from the third and fourth lenses on the optical axis by a distance T34 that satisfies: CT4/T34 is more than 3.0 and less than 6.5.

8. The optical imaging system of claim 1, wherein 1.0 < ETL/EIN < 1.5, wherein ETL is a distance parallel to the optical axis between a position of an object-side surface of the first lens at an 1/2 entrance pupil diameter of the optical imaging system and an imaging plane of the optical imaging system, and EIN is a distance parallel to the optical axis between a position of an object-side surface of the first lens at a 1/2 entrance pupil diameter of the optical imaging system and a position of an image-side surface of the fifth lens at a 1/2 entrance pupil diameter of the optical imaging system.

9. The optical imaging system of claim 1, wherein the edge thickness ET5 of the fifth lens and the edge thickness ET1 of the first lens satisfy: 1.0 < ET5/ET1 < 3.5.

10. The optical imaging system of claim 1, wherein a combined focal length f23 of the second and third lenses and an effective focal length f5 of the fifth lens satisfy: f23/f5 is more than 1.0 and less than 2.0.

11. The optical imaging system of claim 1, wherein a center thickness CT4 of the fourth lens on the optical axis and an edge thickness ET4 of the fourth lens satisfy: 1.5 < CT4/ET4 < 2.0.

12. The optical imaging system of claim 1, wherein a combined focal length f12 of the first and second lenses and a total effective focal length f of the optical imaging system satisfy: f12/f is more than 1.0 and less than 1.5.

13. The optical imaging system of claim 1, wherein the maximum effective radius DT11 of the object-side surface of the first lens, the maximum effective radius DT21 of the object-side surface of the second lens, and the maximum effective radius DT51 of the object-side surface of the fifth lens satisfy: 1.5 < DT51/(DT11+ DT21) < 2.0.

14. The optical imaging system of claim 1, wherein a center thickness CT5 of the fifth lens on the optical axis and a center thickness CT3 of the third lens on the optical axis satisfy: 1.5 < CT5/CT3 < 3.5.

15. The optical imaging system, in order from an object side to an image side along an optical axis, comprises:

a first lens having an optical power;

a second lens having a negative optical power;

a third lens having a negative optical power;

a fourth lens having an optical power; and

a fifth lens having optical power;

1.0＜ETL/EIN＜1.5，

wherein ETL is a distance parallel to the optical axis between a position of an object-side surface of the first lens at an 1/2 entrance pupil diameter of the optical imaging system and an imaging plane of the optical imaging system, EIN is a distance parallel to the optical axis between a position of an object-side surface of the first lens at a 1/2 entrance pupil diameter of the optical imaging system and a position of an image-side surface of the fifth lens at a 1/2 entrance pupil diameter of the optical imaging system.

16. The optical imaging system of claim 15, wherein a sum Σ AT of the separation distances on the optical axis of any two adjacent lenses of the first to fifth lenses and the separation distance T34 on the optical axis of the third and fourth lenses satisfies: 5.5 < Sigma AT/T34 < 9.0.

17. The optical imaging system of claim 15, wherein the total effective focal length f of the optical imaging system, the effective focal length f2 of the second lens, and the effective focal length f4 of the fourth lens satisfy: -2.0 < f/(f2+ f4) < -0.5.

18. The optical imaging system according to claim 15, wherein a separation distance T12 on the optical axis of the first lens and the second lens, a separation distance T23 on the optical axis of the second lens and the third lens, and a separation distance T45 on the optical axis of the fourth lens and the fifth lens satisfy: 1.5 < (T12+ T45)/T23 < 3.5.

19. The optical imaging system of claim 15, wherein an effective focal length f4 of the fourth lens, a radius of curvature R8 of an image-side surface of the fourth lens, and a radius of curvature R10 of an image-side surface of the fifth lens satisfy: 1.1 < f4/(| R8| + R10) < 2.0.

20. The optical imaging system of claim 15, wherein the radius of curvature R2 of the image-side surface of the first lens, the radius of curvature R3 of the object-side surface of the second lens, the radius of curvature R4 of the image-side surface of the second lens, and the radius of curvature R6 of the image-side surface of the third lens satisfy: 2.0 < (| R6| + R3)/(R2+ R4) < 5.0.

21. The optical imaging system of claim 15, wherein a center thickness CT4 of the fourth lens on the optical axis is separated from the third and fourth lenses by a distance T34 on the optical axis that satisfies: CT4/T34 is more than 3.0 and less than 6.5.

22. The optical imaging system of claim 15, wherein the edge thickness ET5 of the fifth lens and the edge thickness ET1 of the first lens satisfy: 1.0 < ET5/ET1 < 3.5.

23. The optical imaging system of claim 15, wherein a combined focal length f23 of the second and third lenses and an effective focal length f5 of the fifth lens satisfy: f23/f5 is more than 1.0 and less than 2.0.

24. The optical imaging system of claim 15, wherein a center thickness CT4 of the fourth lens on the optical axis and an edge thickness ET4 of the fourth lens satisfy: 1.5 < CT4/ET4 < 2.0.

25. The optical imaging system of claim 15, wherein a combined focal length f12 of the first and second lenses and a total effective focal length f of the optical imaging system satisfy: f12/f is more than 1.0 and less than 1.5.

26. The optical imaging system of claim 15, wherein the maximum effective radius DT11 of the object-side surface of the first lens, the maximum effective radius DT21 of the object-side surface of the second lens, and the maximum effective radius DT51 of the object-side surface of the fifth lens satisfy: 1.5 < DT51/(DT11+ DT21) < 2.0.

27. The optical imaging system of claim 15, wherein the fourth lens element has a convex object-side surface and a concave image-side surface.

28. The optical imaging system of claim 15, wherein a center thickness CT5 of the fifth lens on the optical axis and a center thickness CT3 of the third lens on the optical axis satisfy: 1.5 < CT5/CT3 < 3.5.

Images