CN213934372U

CN213934372U - Optical test system

Info

Publication number: CN213934372U
Application number: CN202120234189.6U
Authority: CN
Inventors: 李洋; 刘宾; 贺凌波; 黄林; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2021-08-10
Anticipated expiration: 2031-01-27

Abstract

The application discloses optical test system, it includes range module and optical lens along optical axis preface. The distance increasing module comprises one or more lenses. The optical lens sequentially comprises from an object side to an image side along an optical axis: a diaphragm; a first lens having a positive optical power; a second lens element having a negative refractive power, the object-side surface of which is concave and the image-side surface of which is concave; a third lens with focal power, wherein the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; and a fourth lens having optical power.

Description

Optical test system

Technical Field

The present application relates to the field of optical elements, and in particular, to an optical test system including a pitch module and an optical lens.

Background

Handheld intelligent terminals such as smart phones and tablet computers have been widely used, and the handheld intelligent terminals are provided with cameras with high pixels, so that the photographing requirements of most users can be met. In addition, people also develop a lens with a specific photographing effect, such as a macro lens, which can be installed on the handheld intelligent terminal, so that the photographing function of the handheld intelligent terminal is further enriched.

The macro lens is used as a special lens for macro photography, and is mainly used for shooting very fine objects and realizing detail amplification of the shot objects. The close-up of the macro lens does not depend on an external close-up accessory, all close-up operations are carried out on the lens, and the zoom lens can continuously focus between close-up and infinity, so that the zoom lens can be adjusted to be in a common photographing state from the close-up state, and convenience is provided for a photographer to alternately carry out close-up photographing and common photographing. However, since the object distance of the macro lens is very short, inevitably, the performance of the macro lens is sensitive to the object distance, and therefore, how to realize the test of the macro lens is a difficult problem.

SUMMERY OF THE UTILITY MODEL

The present application provides an optical test system that includes, in order along an optical axis, a range module and an optical lens. The distance increasing module may comprise one or more lenses. The optical lens sequentially comprises from an object side to an image side along an optical axis: a diaphragm; a first lens having a positive optical power; a second lens element having a negative refractive power, the object-side surface of which is concave and the image-side surface of which is concave; a third lens with focal power, wherein the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; and a fourth lens having optical power.

In some embodiments, the optical test system may satisfy: -2.0< f4/f < -0.5, wherein f4 is the effective focal length of the fourth lens and f is the total effective focal length of the optical lens.

In some embodiments, the optical test system may satisfy: -7.5< R2/R1< -2.5, wherein R1 is the radius of curvature of the object-side surface of the first lens and R2 is the radius of curvature of the image-side surface of the first lens.

In some embodiments, the optical test system may satisfy: -4.5< f2/f3< -2.5, wherein f2 is the effective focal length of the second lens and f3 is the effective focal length of the third lens.

In some embodiments, the optical test system may satisfy: 3.0< f1/CT1<4.0, where f1 is the effective focal length of the first lens and CT1 is the central thickness of the first lens along the optical axis.

In some embodiments, the optical test system may satisfy: 1.5< R4/| R5+ R6| <3.0, where R4 is the radius of curvature of the image-side surface of the second lens, R5 is the radius of curvature of the object-side surface of the third lens, and R6 is the radius of curvature of the image-side surface of the third lens.

In some embodiments, the optical test system may satisfy: 1.0< T23/T12<2.1, where T12 is the separation distance of the first lens and the second lens along the optical axis, and T23 is the separation distance of the second lens and the third lens along the optical axis.

In some embodiments, the optical test system may satisfy: 1.0< TL/TTL <1.5, wherein TL is the distance between the image side surface of the distance-increasing module and the diaphragm along the optical axis, and TTL is the distance between the object side surface of the first lens and the imaging surface of the optical lens along the optical axis.

In some embodiments, the optical test system may satisfy: 2.0< f/R8<3.2, where f is the total effective focal length of the optical lens, and R8 is the radius of curvature of the image-side surface of the fourth lens.

In some embodiments, the optical test system may satisfy: 3.0< Σ CT/CT3<4.0, where CT3 is the center thickness of the third lens along the optical axis, and Σ CT is the sum of the center thicknesses of the first to fourth lenses, respectively, along the optical axis.

This application can use parallel light to form the simulation pointolite that is applicable to the macro lens through setting up the range extender module to the realization is to the capability test of macro lens.

Drawings

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

FIG. 1 shows a schematic structural diagram of an optical test system according to embodiment 1 of the present application;

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

FIG. 3 shows a schematic structural diagram of an optical test system according to embodiment 2 of the present application;

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

FIG. 5 shows a schematic structural diagram of an optical test 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 lens of embodiment 3;

FIG. 7 shows a schematic structural diagram of an optical test 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 an optical lens of embodiment 4;

FIG. 9 is a schematic structural diagram showing an optical test system according to embodiment 5 of the present application;

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

FIG. 11 schematically illustrates a point light source required for testing an optical lens; and

fig. 12 shows a schematic diagram of a point light source required for simulation test of an optical lens using a pitch module.

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 image side 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 test system according to an exemplary embodiment of the present application may include a pitch module and an optical lens. The distance increasing module may comprise one or more lenses. The range module can converge parallel light to form a point light source for simulating an object of an optical lens, thereby realizing performance test of a rear optical lens (e.g., a macro lens). The optical lens may include four lenses having optical power, a first lens, a second lens, a third lens, and a fourth lens. The first lens element, the second lens element, the third lens element, the fourth lens element, and the fourth lens element are sequentially arranged along an optical axis from an object side (i.e., a side close to the distance increasing module) to an image side. In the first lens to the fourth lens, any two adjacent lenses may have a spacing distance therebetween.

Fig. 11 schematically shows a point light source required for testing an optical lens, and fig. 12 shows a schematic diagram of a point light source required for simulating a test optical lens using a pitch module.

The optical lens in the optical test system may be a macro lens, which may have a relatively small object distance, e.g., several millimeters to tens of millimeters. When testing the optical performance of the macro lens, a point light source is required to be arranged on the object side of the macro lens. However, since the object distance of the macro lens is too small and the performance of the macro lens is sensitive to the object distance, if a physical point light source is directly disposed on the object side of the macro lens, the performance of the macro lens may not be tested.

The distance-increasing module is arranged in front of the optical lens, and the distance-increasing module is used for simulating a point light source of the optical lens. The distance-increasing module arranged in front of the optical lens needs to be confocal with the optical lens, so that the simulated point light source formed by the distance-increasing module can be used as a shot object of the macro lens, and the performance of the macro lens can be tested. The distance increasing module can convert parallel light, so that the performance of the macro lens can be tested by using the parallel light, and the problems that the point light source is directly used, the setting distance between the point light source and the lens is too short, the testing cannot be carried out and the like are solved.

In some embodiments, the pitch module has an adjustable thickness. For example, the total thickness of the pitch module can be varied by increasing or decreasing the number of lenses.

The optical lens may be a macro lens for implementing close-up photographing. The distance increasing module arranged in front of the macro lens can form a simulation point light source suitable for the macro lens, so that the performance test of the macro lens is realized.

In an exemplary embodiment, the first lens may have a positive optical power; the second lens can have negative focal power, and the object side surface of the second lens is a concave surface; the third lens can have focal power, and the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; and the fourth lens may have optical power. The focal power of the first lens is reasonably configured, so that the macro characteristic of the lens can be ensured, and the larger magnification is realized. The focal power and the surface type of the second lens are reasonably configured, so that the off-axis aberration of the optical lens can be effectively corrected, and the imaging quality is improved. The reasonable configuration of the surface shape of the third lens can ensure the good processability of the third lens, and further reduce the total length of the optical lens, so that the structure is compact. The tolerance sensitivity of the optical lens can be effectively reduced by reasonably configuring the optical power of the fourth lens.

In an exemplary embodiment, the optical lens may further include a stop disposed between the object side and the first lens. An air space is formed between the diaphragm and the distance increasing module, and an air space is also formed between the diaphragm and the first lens. The diaphragm is arranged to control the number of the light beams passing through the first lens to the fourth lens, so that the purpose of adjusting the intensity of the light beam illumination value of the optical lens is achieved.

In an exemplary embodiment, an optical test system according to the present application may satisfy: -2.0< f4/f < -0.5, wherein f4 is the effective focal length of the fourth lens and f is the total effective focal length of the optical lens. The optical lens meets-2.0 < f4/f < -0.5, and can ensure that the optical lens has relatively long-focus characteristic, so that the optical lens has smaller depth of field and larger magnification. In addition, the total length of the optical lens is shortened, and the miniaturization of the optical test system is ensured. Optionally, the fourth lens has a negative optical power.

In an exemplary embodiment, an optical test system according to the present application may satisfy: -7.5< R2/R1< -2.5, wherein R1 is the radius of curvature of the object-side surface of the first lens and R2 is the radius of curvature of the image-side surface of the first lens. The optical test system meets-7.5 < R2/R1< -2.5, is beneficial to the miniaturization of the optical test system, and effectively improves the resolution of the optical test system. Optionally, both the object-side surface and the image-side surface of the first lens may be convex.

In an exemplary embodiment, an optical test system according to the present application may satisfy: -4.5< f2/f3< -2.5, wherein f2 is the effective focal length of the second lens and f3 is the effective focal length of the third lens. The optical test system meets the requirements of-4.5 < f2/f3< -2.5, and can realize reasonable distribution of the focal length of the optical lens, thereby effectively correcting various aberrations and achieving the purpose of improving the resolution of the optical test system.

In an exemplary embodiment, an optical test system according to the present application may satisfy: 3.0< f1/CT1<4.0, where f1 is the effective focal length of the first lens and CT1 is the central thickness of the first lens along the optical axis. The optical power of the first lens can be reasonably distributed when the requirement that the power is 3.0< f1/CT1<4.0 is met, so that various aberrations can be corrected conveniently, and the resolution of an optical test system is improved. For example, f1 and CT1 may satisfy 3.3< f1/CT1< 3.8.

In an exemplary embodiment, an optical test system according to the present application may satisfy: 1.5< R4/| R5+ R6| <3.0, where R4 is the radius of curvature of the image-side surface of the second lens, R5 is the radius of curvature of the object-side surface of the third lens, and R6 is the radius of curvature of the image-side surface of the third lens. The optical test system meets the requirement that 1.5< R4/| R5+ R6| <3.0, is favorable for reducing aberration and improves the imaging quality of the optical test system.

In an exemplary embodiment, an optical test system according to the present application may satisfy: 1.0< T23/T12<2.1, where T12 is the separation distance of the first lens and the second lens along the optical axis, and T23 is the separation distance of the second lens and the third lens along the optical axis. The optical lens meets the requirement that 1.0< T23/T12<2.1, is beneficial to reasonably distributing the distance among the first lens, the second lens and the third lens, further effectively reduces the thickness sensitivity of the optical lens and corrects the curvature of field of the optical lens.

In an exemplary embodiment, an optical test system according to the present application may satisfy: 1.0< TL/TTL <1.5, wherein TL is the distance between the image side surface of the distance-increasing module and the diaphragm along the optical axis, and TTL is the distance between the object side surface of the first lens and the imaging surface of the optical lens along the optical axis. The optical lens meets the condition that TL/TTL is more than 1.0 and less than 1.5, is beneficial to reducing the influence of the aberration of the distance-increasing module on a test result, improves the imaging quality of the optical lens and ensures the miniaturization of an optical test system.

In an exemplary embodiment, an optical test system according to the present application may satisfy: 2.0< f/R8<3.2, where f is the total effective focal length of the optical test system and R8 is the radius of curvature of the image-side surface of the fourth lens. The requirement that f/R8 is more than 2.0 and less than 3.2 is met, the spherical aberration is eliminated, and the imaging quality is improved. Alternatively, the image side surface of the fourth lens may be concave.

In an exemplary embodiment, an optical test system according to the present application may satisfy: 3.0< ∑ CT/CT3<4.0, where CT3 is the central thickness of the third lens along the optical axis, and Σ CT is the sum of the central thicknesses of the first lens to the fourth lens, respectively, along the optical axis. The requirement that 3.0< ∑ CT/CT3 is less than 4.0 is met, the central thickness of the third lens is favorably and reasonably distributed, the third lens is easy to perform injection molding, the machinability of the whole optical lens is further improved, and meanwhile, the better imaging quality of the optical lens is guaranteed.

In an exemplary embodiment, an optical lens according to the present application may further include a filter for correcting color deviation and/or a protective glass for protecting a photosensitive element located on an image forming surface.

The optical lens according to the above-described embodiment of the present application may employ a plurality of lenses, for example, four lenses as described above. The optical lens has the characteristics of a macro lens by reasonably distributing the focal power, the surface type, the center thickness of each lens, the on-axis distance between each lens and the like, can meet the requirement of close-range shooting, and can realize detail amplification of a shot object.

In addition, the volume of the optical testing system can be effectively reduced and the machinability of the optical testing system can be improved by reasonably configuring the distance increasing module and the optical lens. Particularly, by providing the distance increasing module, a simulated point light source suitable for the macro lens can be formed using parallel light, thereby realizing a performance test of the optical lens having the macro lens characteristic.

In the embodiments of the present application, at least one of the mirror surfaces of each lens in the optical lens is an aspherical mirror, that is, at least one of the object-side surface of the first lens to the image-side surface of the fourth lens is an aspherical mirror. 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 lens center to the lens periphery, an aspherical lens has a better curvature radius characteristic, and has an advantage of improving distortion aberration, that is, astigmatic aberration. After the aspheric lens is adopted, the aberration generated in imaging can be eliminated as much as possible, and the imaging quality is further improved. Optionally, at least one of the object-side surface and the image-side surface of each of the first lens, the second lens, the third lens, and the fourth lens is an aspheric mirror surface. Optionally, each of the first, second, third, and fourth lenses has an object-side surface and an image-side surface that are aspheric mirror surfaces.

However, it will be understood by those skilled in the art that the number of lenses constituting the optical lens may be varied to obtain the respective results and advantages described in the present specification without departing from the technical solutions claimed in the present application. For example, although four lenses are exemplified in the embodiment, the optical lens is not limited to including four lenses. The optical lens may also include other numbers of lenses, if desired.

Specific examples of optical test systems that can be adapted for use with the above-described embodiments are further described below with reference to the accompanying drawings.

Example 1

An optical test system according to embodiment 1 of the present application is described below with reference to fig. 1 to 2D. Fig. 1 shows a schematic structural diagram of an optical test system according to embodiment 1 of the present application.

As shown in fig. 1, the optical test system may include a pitch module T and an optical lens. The optical lens may include, in order from an object side to an image side along an optical axis: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a filter E5, and an image plane S11.

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

Basic parameters of the optical test system of example 1 are shown in table 1, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm).

TABLE 1

In this example, the distance increasing module T may be one or more lenses and has a total thickness D. The total effective focal length f of the optical lens is 1.19mm, the total length TTL of the optical lens (i.e., the distance along the optical axis from the object-side surface S1 of the first lens E1 to the imaging surface S11 of the optical lens) is 3.10mm, the half ImgH of the diagonal length of the effective pixel area on the imaging surface S11 of the optical lens is 1.81mm, the aperture value Fno of the optical lens is 3.04, and the maximum half field angle Semi-FOV of the optical lens is 38.4 °.

In embodiment 1, the object-side surface and the image-side surface of any one of the first lens E1 to the fourth lens E4 are aspheric surfaces, and the surface shape x of the 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 shows the high-order coefficient coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 which can be used for each of the aspherical mirror surfaces S1-S8 in example 1.

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

6.1608E-04

-7.2288E-04

-1.2829E-04

-1.6449E-05

-7.2890E-06

9.8323E-07

-2.0162E-06

4.0877E-07

9.6288E-08

S2

-3.1456E-02

-2.1763E-03

-1.1497E-04

-2.1753E-05

-6.3053E-07

-8.5449E-07

7.0880E-07

-1.2280E-06

4.4855E-07

S3

-5.4421E-02

-9.8439E-04

4.5667E-04

1.3463E-04

-1.1315E-05

9.5229E-06

-4.1410E-06

3.0295E-06

-2.6146E-06

S4

-5.1223E-02

7.1513E-03

2.7081E-03

3.5645E-05

-3.7741E-04

-3.4993E-04

-2.9469E-04

-1.8507E-04

-9.3199E-05

S5

-2.3277E-02

-2.3171E-03

1.8257E-04

-6.7296E-04

-7.6435E-04

-1.3855E-04

-5.8474E-06

1.1119E-04

1.7470E-04

S6

-1.4358E-01

7.6368E-02

-1.0878E-02

3.3643E-03

-5.8705E-03

1.6395E-03

-4.3542E-04

5.8827E-04

-2.2007E-04

S7

-3.2517E-01

1.0297E-01

-3.1278E-02

9.3043E-03

-5.3882E-03

3.4739E-03

-1.6855E-03

9.7396E-04

-5.7179E-04

S8

-7.8857E-01

1.2212E-01

-5.0046E-02

1.2792E-02

-9.5504E-03

4.2218E-03

-1.9018E-03

5.5467E-04

-1.1668E-03

TABLE 2

Fig. 2A shows an on-axis chromatic aberration curve of the optical lens of embodiment 1, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the optical lens. Fig. 2B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 1. Fig. 2C shows a distortion curve of the optical lens 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 lens of embodiment 1, which represents a deviation of different image heights on an image plane of light rays after passing through the optical lens. As can be seen from fig. 2A to 2D, the optical lens system of embodiment 1 can achieve good imaging quality.

Example 2

An optical test 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 test system according to embodiment 2 of the present application.

As shown in fig. 3, the optical test system may include a pitch module T and an optical lens. The optical lens may include, in order from an object side to an image side along an optical axis: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a filter E5, and an image plane S11.

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

In this example, the distance increasing module T may be one or more lenses and has a total thickness D. The total effective focal length f of the optical lens is 1.28mm, the total length TTL of the optical lens is 3.50mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S11 of the optical lens is 1.81mm, the aperture value Fno of the optical lens is 3.04, and the maximum half field angle Semi-FOV of the optical lens is 38.7 °.

Basic parameters of the optical test system of example 2 are shown in table 3, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 4 shows the high-order term coefficients a4, a6, A8, a10, a12, a14, a16, a18, and a20 that can be used for each of the aspherical mirror surfaces S1 through S8 in example 2, wherein each aspherical mirror surface type can be defined by the formula (1) given in example 1 above.

TABLE 3

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

-4.3823E-03

-2.0832E-03

-4.2472E-04

-9.3780E-05

-2.1870E-05

1.9690E-06

2.1470E-06

3.4805E-06

9.0668E-08

S2

-5.7229E-02

-4.8191E-03

-5.9742E-04

-1.1047E-04

-1.3909E-05

1.0985E-05

1.2643E-05

6.5637E-06

3.6330E-06

S3

-8.2942E-02

8.3952E-04

1.1724E-03

3.2748E-04

-5.2856E-05

1.0468E-05

-1.2128E-05

4.2600E-06

-4.1102E-06

S4

-6.9995E-02

7.5475E-03

1.9404E-03

7.0050E-04

-4.8447E-05

7.4450E-05

-1.0931E-05

6.1407E-06

-8.8030E-06

S5

-9.1541E-03

8.0425E-03

7.7608E-03

3.2366E-03

-6.6272E-04

-2.8196E-04

-2.7587E-04

-9.2038E-06

3.1341E-05

S6

-1.8033E-01

4.7205E-02

5.0386E-03

6.5670E-03

4.9123E-04

2.2066E-04

-5.8096E-04

-5.0423E-04

-5.9756E-04

S7

-3.5995E-02

-5.0616E-02

2.6148E-02

-1.2695E-02

5.5638E-03

-1.9623E-03

8.8139E-04

-6.8927E-04

-3.4714E-06

S8

-5.7271E-01

5.3858E-02

-1.5100E-02

4.5973E-04

9.0654E-04

-4.2300E-04

8.1309E-04

-4.7038E-04

1.6808E-04

TABLE 4

Fig. 4A shows an on-axis chromatic aberration curve of the optical lens of embodiment 2, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the optical lens. Fig. 4B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 2. Fig. 4C shows a distortion curve of the optical lens 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 lens of embodiment 2, which represents a deviation of different image heights on an image plane of light rays after passing through the optical lens head. As can be seen from fig. 4A to 4D, the optical lens according to embodiment 2 can achieve good imaging quality.

Example 3

An optical test 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 test system according to embodiment 3 of the present application.

As shown in fig. 5, the optical test system may include a pitch module T and an optical lens. The optical lens may include, in order from an object side to an image side along an optical axis: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a filter E5, and an image plane S11.

In this example, the distance increasing module T may be one or more lenses and has a total thickness D. The total effective focal length f of the optical lens is 1.19mm, the total length TTL of the optical lens is 3.10mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S11 of the optical lens is 1.81mm, the aperture value Fno of the optical lens is 3.04, and the maximum half field angle Semi-FOV of the optical lens is 38.4 °.

Basic parameters of the optical test system of example 3 are shown in table 5, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 6 shows the high-order term coefficients a4, a6, A8, a10, a12, a14, a16, a18, and a20 that can be used for each of the aspherical mirror surfaces S1 through S8 in example 3, wherein each aspherical mirror surface type can be defined by the formula (1) given in example 1 above.

TABLE 5

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

5.8442E-04

-7.2938E-04

-1.2906E-04

-1.6548E-05

-7.4085E-06

9.8217E-07

-2.0345E-06

4.4500E-07

8.5220E-08

S2

-3.1512E-02

-2.1644E-03

-1.1434E-04

-2.1961E-05

-7.5340E-07

-8.8584E-07

6.2850E-07

-1.2104E-06

4.5451E-07

S3

-5.4329E-02

-9.4956E-04

4.5633E-04

1.3473E-04

-1.2569E-05

9.9462E-06

-4.5270E-06

3.1842E-06

-2.8257E-06

S4

-5.1291E-02

7.0091E-03

2.6376E-03

2.4082E-06

-3.8399E-04

-3.4920E-04

-2.9053E-04

-1.8205E-04

-9.1041E-05

S5

-2.3983E-02

-2.4999E-03

1.3101E-04

-7.6509E-04

-7.9095E-04

-1.4328E-04

1.5499E-05

1.2307E-04

1.7685E-04

S6

-1.4319E-01

7.5073E-02

-9.9884E-03

2.8542E-03

-5.7434E-03

1.5666E-03

-3.0702E-04

6.1483E-04

-1.6310E-04

S7

-3.2259E-01

1.0329E-01

-3.1324E-02

9.2706E-03

-5.3730E-03

3.4664E-03

-1.6948E-03

9.7199E-04

-5.7372E-04

S8

-7.8893E-01

1.2325E-01

-5.0183E-02

1.2817E-02

-9.6509E-03

4.2407E-03

-1.9096E-03

5.8161E-04

-1.1356E-03

TABLE 6

Fig. 6A shows an on-axis chromatic aberration curve of the optical lens of embodiment 3, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the optical lens. Fig. 6B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 3. Fig. 6C shows a distortion curve of the optical lens 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 lens of example 3, which represents a deviation of different image heights on an image plane of light rays after passing through the optical lens. As can be seen from fig. 6A to 6D, the optical lens system of embodiment 3 can achieve good imaging quality.

Example 4

An optical test 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 test system according to embodiment 4 of the present application.

As shown in fig. 7, the optical test system may include a pitch module T and an optical lens. The optical lens may include, in order from an object side to an image side along an optical axis: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a filter E5, and an image plane S11.

In this example, the distance increasing module T may be one or more lenses and has a total thickness D. The total effective focal length f of the optical lens is 1.17mm, the total length TTL of the optical lens is 3.10mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S11 of the optical lens is 1.81mm, the aperture value Fno of the optical lens is 3.04, and the maximum half field angle Semi-FOV of the optical lens is 38.1 °.

Basic parameters of the optical test system of example 4 are shown in table 7, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 8 shows the high-order term coefficients a4, a6, A8, a10, a12, a14, a16, a18, and a20 that can be used for each of the aspherical mirror surfaces S1 through S8 in example 4, wherein each aspherical mirror surface type can be defined by the formula (1) given in example 1 above.

TABLE 7

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

1.2685E-03

-6.3611E-04

-1.3524E-04

-9.8139E-06

-9.9107E-06

3.2700E-06

-2.8496E-06

1.1218E-06

-2.4444E-07

S2

-3.0166E-02

-2.5586E-03

-1.3712E-04

-2.4687E-05

1.5717E-06

-3.2710E-07

-6.6190E-08

-1.2652E-06

4.9307E-07

S3

-5.4295E-02

-1.8429E-03

4.3813E-04

1.7076E-04

-6.9252E-06

1.3570E-05

-5.3759E-06

3.1807E-06

-4.1936E-06

S4

-5.0398E-02

7.1779E-03

4.1887E-03

4.5784E-04

-3.3659E-04

-4.0154E-04

-3.6086E-04

-2.3761E-04

-1.1692E-04

S5

-2.0761E-02

-1.5796E-03

6.3439E-04

-1.6368E-03

-1.7714E-03

-7.5396E-04

-2.0609E-04

1.8899E-04

4.2598E-04

S6

-1.4519E-01

7.6316E-02

-8.8369E-03

-6.4441E-04

-5.5140E-03

2.0539E-03

6.7708E-04

9.2361E-04

1.8305E-04

S7

-2.9890E-01

1.0502E-01

-3.2132E-02

8.5621E-03

-4.6899E-03

3.1528E-03

-1.7081E-03

8.7113E-04

-5.8814E-04

S8

-7.5177E-01

1.2896E-01

-4.7179E-02

1.0002E-02

-9.0397E-03

3.4546E-03

-1.6961E-03

1.0559E-04

-1.0503E-03

TABLE 8

Fig. 8A shows an on-axis chromatic aberration curve of the optical lens of embodiment 4, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the optical lens. Fig. 8B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 4. Fig. 8C shows a distortion curve of the optical lens 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 lens of example 4, which represents a deviation of different image heights on an image forming surface of light rays after passing through the optical lens. As can be seen from fig. 8A to 8D, the optical lens system of embodiment 4 can achieve good imaging quality.

Example 5

An optical test 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 test system according to embodiment 5 of the present application.

As shown in fig. 9, the optical test system may include a pitch module T and an optical lens. The optical lens may include, in order from an object side to an image side along an optical axis: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a filter E5, and an image plane S11.

In this example, the distance increasing module T may be one or more lenses and has a total thickness D. The total effective focal length f of the optical lens is 1.25mm, the total length TTL of the optical lens is 3.10mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S11 of the optical lens is 1.81mm, the aperture value Fno of the optical lens is 3.04, and the maximum half field angle Semi-FOV of the optical lens is 38.1 °.

Basic parameters of the optical test system of example 5 are shown in table 9, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 10 shows the high-order term coefficients a4, a6, A8, a10, a12, a14, a16, a18, and a20 that can be used for each of the aspherical mirror surfaces S1 through S8 in example 5, wherein each aspherical mirror surface type can be defined by the formula (1) given in example 1 above.

TABLE 9

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

-2.9963E-04

-9.0181E-04

-1.3731E-04

-2.1023E-05

-4.4603E-06

5.6566E-07

-3.8030E-07

-4.8689E-07

1.7748E-07

S2

-3.2521E-02

-1.4990E-03

-1.7883E-06

-2.3314E-05

3.0967E-06

-2.3091E-06

1.2697E-06

-1.4206E-06

6.3942E-07

S3

-5.1954E-02

4.5162E-04

7.6924E-04

1.1064E-04

-5.3628E-06

8.9922E-06

-2.4134E-06

3.9441E-06

-1.6733E-06

S4

-3.5345E-02

3.3550E-03

1.3317E-03

-5.1485E-04

-5.9634E-04

-5.7029E-04

-4.3238E-04

-2.5912E-04

-1.2183E-04

S5

-2.3893E-02

-9.7702E-03

-3.6776E-03

-1.5302E-03

-4.0875E-04

-1.8222E-04

-8.5828E-05

4.1772E-04

7.5616E-04

S6

-1.1869E-01

5.7682E-02

-9.0105E-03

-4.5109E-03

-9.8609E-04

2.0910E-03

2.1385E-03

2.2627E-03

2.0644E-03

S7

-4.4922E-02

-1.0144E-02

1.2608E-02

-1.1030E-02

9.2862E-03

-1.3689E-03

4.2524E-03

1.1603E-03

2.7251E-03

S8

-1.0682E+00

1.8779E-01

-7.7468E-02

2.9526E-02

-8.3178E-03

1.1610E-02

2.5300E-03

5.6268E-03

3.1202E-03

Watch 10

Fig. 10A shows an on-axis chromatic aberration curve of the optical lens of embodiment 5, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the optical lens. Fig. 10B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of example 5. Fig. 10C shows a distortion curve of the optical lens 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 lens of example 5, which represents a deviation of different image heights on an image forming surface of light rays after passing through the optical lens. As can be seen from fig. 10A to 10D, the optical lens system of embodiment 5 can achieve good imaging quality.

In summary, examples 1 to 5 satisfy the relationships shown in table 11, respectively.

Conditions/examples	1	2	3	4	5
						f4/f	-1.80	-0.86	-1.68	-1.72	-0.88
R2/R1	-6.03	-2.71	-6.02	-7.19	-4.26
						f2/f3	-2.78	-3.05	-2.92	-3.17	-4.28
f1/CT1	3.51	3.77	3.51	3.42	3.40
						R4/\|R5+R6\|	1.86	1.83	1.84	2.20	2.72
T23/T12	2.00	1.15	2.02	1.67	2.07
						TL/TTL	1.35	1.19	1.35	1.31	1.45
f/R8	3.13	2.10	3.11	2.99	2.06
						∑CT/CT3	3.22	3.07	3.21	3.25	3.71

TABLE 11

The present application also provides an image pickup apparatus, the electronic photosensitive element of which may be a photosensitive coupled element (CCD) or a complementary metal oxide semiconductor element (CMOS). The camera device may be a stand-alone camera device such as a digital camera, or may be a camera module integrated on a mobile electronic device such as a mobile phone. The image pickup apparatus is equipped with the optical lens 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 those skilled in the art that the scope of the invention herein disclosed is not limited to the particular combination of features described above, but also encompasses other arrangements formed by any combination of the above 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

1. An optical test system comprising, in order along an optical axis:

a pitch module comprising one or more lenses; and

the optical lens sequentially comprises from an object side to an image side along the optical axis:

a diaphragm;

a first lens having a positive optical power;

a second lens element having a negative refractive power, the object-side surface of which is concave and the image-side surface of which is concave;

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

a fourth lens having optical power.

2. The optical test system of claim 1, wherein-2.0 < f4/f < -0.5,

where f4 is the effective focal length of the fourth lens, and f is the total effective focal length of the optical lens.

3. The optical test system of claim 1, characterized by-7.5 < R2/R1< -2.5,

wherein R1 is a radius of curvature of an object-side surface of the first lens, and R2 is a radius of curvature of an image-side surface of the first lens.

4. The optical test system of claim 1, characterized by-4.5 < f2/f3< -2.5,

wherein f2 is the effective focal length of the second lens and f3 is the effective focal length of the third lens.

5. The optical testing system of claim 1, wherein 3.0< f1/CT1<4.0,

where f1 is the effective focal length of the first lens and CT1 is the center thickness of the first lens along the optical axis.

6. The optical testing system of claim 1, wherein 1.5< R4/| R5+ R6| <3.0,

wherein R4 is a radius of curvature of an image-side surface of the second lens, R5 is a radius of curvature of an object-side surface of the third lens, and R6 is a radius of curvature of an image-side surface of the third lens.

7. The optical testing system of claim 1, wherein 1.0< T23/T12<2.1,

wherein T12 is a separation distance of the first and second lenses along the optical axis, and T23 is a separation distance of the second and third lenses along the optical axis.

8. The optical test system of claim 1, wherein 1.0< TL/TTL <1.5,

wherein TL is a distance between an image side surface of the distance increasing module and the diaphragm along the optical axis, and TTL is a distance between an object side surface of the first lens element and an imaging surface of the optical lens along the optical axis.

9. The optical test system of claim 1, wherein 2.0< f/R8<3.2,

where f is the total effective focal length of the optical lens, and R8 is the radius of curvature of the image-side surface of the fourth lens.

10. The optical test system according to any of claims 1 to 9, characterized in that 3.0< Σ CT/CT3<4.0,

wherein CT3 is a center thickness of the third lens along the optical axis, and Σ CT is a sum of center thicknesses of the first lens to the fourth lens along the optical axis, respectively.