CN106932886B - Iris lens - Google Patents

Abstract

The application provides an iris lens which sequentially comprises a first lens and a second lens from an object side to an image side along an optical axis. The first lens has positive focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative focal power, and the distance T12 between the first lens and the second lens on the optical axis and the distance TTL between the object side surface of the first lens and the imaging surface of the iris lens on the optical axis satisfy T12/TTL > 0.32.

Description

Iris lens

Technical Field

The present invention relates to an iris lens, and more particularly, to an iris lens including two lenses.

Background

In recent years, with the development of science and technology, portable electronic products have been gradually raised, and more people enjoy portable electronic products having an image capturing function, so that the demand of the market for an image capturing lens suitable for portable electronic products has been gradually increased. The photosensitive element of the currently used camera lens is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor). With the advancement of semiconductor process technology, the optical system tends to have higher pixels, and the pixel size of the chip becomes smaller and smaller, which puts higher demands on the high imaging quality and miniaturization of the lens used in cooperation.

Especially in the field of security protection, the requirements for the lens with iris recognition are higher and higher, and not only the compactness of the lens structure needs to be ensured, but also the brightness and the image resolving power of the lens need to be improved so as to improve the recognition accuracy of the lens.

Therefore, it is desirable to provide a compact iris lens having high brightness, high resolution, and a simple structure.

Disclosure of Invention

The technical solution provided by the present application at least partially solves the technical problems described above.

According to an aspect of the present application, there is provided an iris lens including, in order from an object side to an image side along an optical axis, a first lens and a second lens. The first lens has positive focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative focal power, and the distance T12 between the first lens and the second lens on the optical axis and the distance TTL between the object side surface of the first lens and the imaging surface of the iris lens on the optical axis can satisfy T12/TTL > 0.32.

The present application adopts a plurality of (e.g., two) lenses, and by reasonably distributing the focal power and the surface type of each lens of the optical lens, the system has the advantages of high relative illumination and high resolution in the process of simplifying the lens structure.

According to another aspect of the present application, there is provided an iris lens including, in order from an object side to an image side along an optical axis, a first lens and a second lens. The first lens has positive focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative power, and the effective radius DT11 of the object side surface of the first lens and the effective radius DT22 of the image side surface of the second lens can satisfy 0.7< DT11/DT22 <1.

In one embodiment, 1< ET1max/ET1min <1.45 may be satisfied between a maximum thickness ET1max of the first lens in a direction parallel to the optical axis and a minimum thickness ET1min of the first lens in the direction parallel to the optical axis.

In one embodiment, the iris lens further includes an electron photosensitive element disposed on the imaging surface, wherein a maximum incident angle CRAmax of the chief ray incident on the electron photosensitive element may satisfy CRAmax <30 °.

In one embodiment, 0.5< ET1/CT1<1 can be satisfied between the edge thickness ET1 of the first lens and the central thickness CT1 of the first lens on the optical axis.

In one embodiment, the iris lens further includes a filter disposed between the second lens and the imaging surface, the filter being an IR infrared filter.

In one embodiment, the band pass band of the IR infrared filter may be about 785nm to about 835 nm.

In one embodiment, a distance TTL from the object side surface of the first lens element to the imaging surface of the iris lens on the optical axis, ImgH which is half of the diagonal length of the effective pixel area of the electronic photosensitive element on the imaging surface of the iris lens, and the total effective focal length of the iris lens can satisfy 0.4mm^-1<TTL/(ImgH*f)<0.7mm^-1。

In one embodiment, an effective radius DT12 of the image-side surface of the first lens and an effective radius DT22 of the image-side surface of the second lens may satisfy 0.7< DT12/DT22 <1.

In one embodiment, an effective radius DT22 of the image-side surface of the second lens and an ImgH of a half of a diagonal length of an effective pixel region of the electron-sensitive element on the imaging surface of the iris lens may satisfy 0.5< DT22/ImgH <1.

In one embodiment, the iris lens further includes an aperture stop disposed between the object side and the first lens, and a radius of curvature R4 of the image-side surface of the second lens and a total effective focal length f of the iris lens may satisfy | R4/f | < 3.

In one embodiment, the iris lens further includes an aperture stop disposed between the first lens and the second lens, and a radius of curvature R2 of the image-side surface of the first lens and an effective focal length f1 of the first lens may satisfy 0.5< R2/f1< 0.9.

Through the iris lens configured as above, there can be further at least one of advantageous effects such as high recognition accuracy, effective correction of aberration, effective correction of curvature of field, shortening of the total system length, and the like.

Drawings

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

fig. 1 is a schematic structural diagram of an iris lens according to embodiment 1 of the present application;

fig. 2A shows an on-axis chromatic aberration curve of the iris lens of embodiment 1;

fig. 2B shows an astigmatism curve of the iris lens of embodiment 1;

fig. 2C shows a distortion curve of the iris lens of embodiment 1;

fig. 2D shows a chromatic aberration of magnification curve of the iris lens of embodiment 1;

fig. 2E shows a relative illuminance curve of the iris lens of embodiment 1;

fig. 3 is a schematic structural diagram of an iris lens according to embodiment 2 of the present application;

fig. 4A shows an on-axis chromatic aberration curve of the iris lens of embodiment 2;

fig. 4B shows an astigmatism curve of the iris lens of embodiment 2;

fig. 4C shows a distortion curve of the iris lens of embodiment 2;

fig. 4D shows a chromatic aberration of magnification curve of the iris lens of embodiment 2;

fig. 4E shows a relative illuminance curve of the iris lens of embodiment 2;

fig. 5 is a schematic view showing a structure of an iris lens according to embodiment 3 of the present application;

fig. 6A shows an on-axis chromatic aberration curve of the iris lens of embodiment 3;

fig. 6B shows an astigmatism curve of the iris lens of embodiment 3;

fig. 6C shows a distortion curve of the iris lens of embodiment 3;

fig. 6D shows a chromatic aberration of magnification curve of the iris lens of embodiment 3;

fig. 6E shows a relative illuminance curve of the iris lens of embodiment 3;

fig. 7 is a schematic structural diagram of an iris lens according to embodiment 4 of the present application;

fig. 8A shows an on-axis chromatic aberration curve of the iris lens of embodiment 4;

fig. 8B shows an astigmatism curve of the iris lens of embodiment 4;

fig. 8C shows a distortion curve of the iris lens of embodiment 4;

fig. 8D shows a chromatic aberration of magnification curve of the iris lens of embodiment 4;

fig. 8E shows a relative illuminance curve of the iris lens of embodiment 4;

fig. 9 is a schematic view showing a structure of an iris lens according to embodiment 5 of the present application;

fig. 10A shows an on-axis chromatic aberration curve of the iris lens of embodiment 5;

fig. 10B shows an astigmatism curve of the iris lens of embodiment 5;

fig. 10C shows a distortion curve of the iris lens of embodiment 5;

fig. 10D shows a chromatic aberration of magnification curve of the iris lens of embodiment 5;

fig. 10E shows a relative illuminance curve of the iris lens of embodiment 5;

fig. 11 is a schematic view showing a structure of an iris lens according to embodiment 6 of the present application;

fig. 12A shows an on-axis chromatic aberration curve of the iris lens of embodiment 6;

fig. 12B shows an astigmatism curve of the iris lens of embodiment 6;

fig. 12C shows a distortion curve of the iris lens of embodiment 6;

fig. 12D shows a chromatic aberration of magnification curve of the iris lens of embodiment 6;

fig. 12E shows a relative illuminance curve of the iris lens of example 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 the present specification, expressions such as first, second, etc. are used only for distinguishing one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below may also be referred to as the second 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.

The paraxial region refers to a region near the optical axis. Herein, a surface closest to the object in each lens is referred to as an object side surface, and a surface closest to the imaging surface in each lens is referred to as an image side surface.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "has," "including," and/or "including," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, 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 iris lens according to an exemplary embodiment of the present application includes, for example, two lenses, i.e., a first lens and a second lens. The first lens and the second lens are arranged in order from an object side to an image side along an optical axis.

In an exemplary embodiment, the first lens may have a positive optical power, with a convex object-side surface and a concave image-side surface; and the second lens may have a negative optical power.

Optionally, the iris lens may further include a filter disposed between the second lens and the imaging surface. The filter can be an IR (infrared) filter which can be used for filtering visible light noise, so that the high-performance identification effect of the lens is realized. The band pass band of the filter can be about 785nm to about 835nm to ensure that the irises of different human eyeball colors can be correctly identified.

In an exemplary embodiment, a distance T12 between an on-axis separation of the first lens and the second lens and an on-axis distance TTL from an object side surface of the first lens to an image plane of the iris lens may satisfy T12/TTL >0.32, and more specifically, T12 and TTL may further satisfy 0.33 ≦ T12/TTL ≦ 0.43. The distance T12 between the first lens and the second lens and the distance TTL between the object side surface of the first lens and the imaging surface of the iris lens can reduce the incident angle of light and optical aberration, thereby improving the resolution of the lens.

In order to miniaturize the lens, the effective radius of each mirror surface can be optimized. For example, 0.7< DT11/DT22<1 can be satisfied between the effective radius DT11 of the object-side surface of the first lens and the effective radius DT22 of the image-side surface of the second lens, and more specifically, DT11 and DT22 can further satisfy 0.80 ≦ DT11/DT22 ≦ 0.99. For another example, an effective radius DT12 of the image-side surface of the first lens and an effective radius DT22 of the image-side surface of the second lens may satisfy 0.7< DT12/DT22<1, and more specifically, DT12 and DT22 may further satisfy 0.72 ≦ DT12/DT22 ≦ 0.86.

In addition, in order to achieve good matching with a chip while achieving miniaturization of the lens size, the effective radius DT22 of the image-side surface of the second lens and the half ImgH of the diagonal length of the effective pixel region of the electron-sensitive element on the imaging surface of the iris lens may be arranged appropriately. DT22 and ImgH may satisfy 0.5< DT22/ImgH <1, more specifically DT22 and ImgH may further satisfy 0.56 ≦ DT22/ImgH ≦ 0.79.

In an exemplary embodiment, 1< ET1max/ET1min <1.45 may be satisfied between a maximum thickness ET1max of the first lens in a direction parallel to the optical axis and a minimum thickness ET1min of the first lens in a direction parallel to the optical axis, and more particularly, ET1max and ET1min may further satisfy 1.10 ≦ ET1max/ET1min ≦ 1.40 to secure the optical power of the first lens, thereby securing the recognition accuracy of the iris lens.

In an exemplary embodiment, 0.5< ET1/CT1<1 may be satisfied between the edge thickness ET1 of the first lens and the center thickness CT1 of the first lens on the optical axis, and more particularly, ET1 and CT1 may further satisfy 0.53 ≦ ET1/CT1 ≦ 0.74 to ensure that the overall power of the first lens from the center to the edge is positive, thereby ensuring the recognition accuracy of the iris lens.

In order to effectively reduce the film system drift under the incident angle of the peripheral field of view, the film system bandwidth is reduced, and therefore the interference effect is reduced. The maximum incidence angle of the chief ray incident on the electronic photosensitive element can be optimized. The maximum incidence angle CRAmax of the main light incident on the electron-sensitive element may satisfy CRAmax <30 °, and more specifically, CRAmax may further satisfy CRAmax < 29.03 ° of 24.14 °. Such configuration can also promote the sensitization efficiency that light got into the chip effectively to promote the recognition effect of iris camera lens.

The on-axis distance TTL from the object side surface of the first lens to the imaging surface of the iris lens, the half ImgH of the diagonal length of the effective pixel area of the electronic photosensitive element on the imaging surface of the iris lens and the total effective focal length of the iris lens can meet the requirement of 0.4mm^-1<TTL/(ImgH*f)<0.7mm^-1More specifically, TTL, ImgH, and f can further satisfy 0.61mm^-1≤TTL/(ImgH*f)≤0.67mm^-1. To ensure that the iris lens has sufficient recognition accuracy while ensuring that the lens size is as small as possible.

In some embodiments, an aperture stop for limiting the light beam may be disposed between the object side and the first lens to improve the imaging quality of the lens. At this time, a radius of curvature R4 of the image-side surface of the second lens and the total effective focal length f of the iris lens may satisfy | R4/f | <3, and more particularly, R4 and f may further satisfy | R4/f | ≦ 2.98 of 0.65 ≦ to achieve high luminance and high resolving power of the iris lens.

In other embodiments, an aperture stop for limiting the light beam may be disposed between the first lens and the second lens to improve the imaging quality of the lens. At this time, a curvature radius R2 of the image side surface of the first lens and an effective focal length f1 of the first lens can satisfy 0.5< R2/f1<0.9, and more specifically, 0.73 ≦ R2/f1 ≦ 0.81, so as to reduce the coma effect and improve the resolving power of the lens.

According to the iris lens of the above embodiment of the present application, a plurality of lenses can be adopted, and 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, the structure of the iris lens can be effectively compact, and the miniaturization of the iris lens can be ensured, so that the iris lens is more beneficial to production and processing and is applicable to portable electronic products. In the embodiment of the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. The aspheric lens is characterized in that: the curvature varies continuously from the center to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center 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.

However, it will be appreciated by those skilled in the art that the number of lenses constituting the lens barrel 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 two lenses are exemplified in the embodiment, the iris lens is not limited to include two lenses. The iris lens may also include other numbers of lenses, if desired.

Specific examples of the iris lens applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

Example 1

An iris lens according to embodiment 1 of the present application is described below with reference to fig. 1 to 2E. Fig. 1 shows a schematic structural diagram of an iris lens according to embodiment 1 of the present application.

As shown in fig. 1, the iris lens includes two lenses L1 and L2 arranged in order from the object side to the image side along the optical axis. A first lens L1 having an object side surface S1 and an image side surface S2; and a second lens L2 having an object-side surface S3 and an image-side surface S4. Optionally, the iris lens may further include a filter L3 having an object side S5 and an image side S6. The filter L3 may be an IR infrared filter with a bandpass band of about 785nm to about 835 nm. In the iris lens of the present embodiment, a stop STO for limiting a light beam may be further provided between the object side and the first lens L1 to improve the imaging quality. The light from the object passes through the respective surfaces S1 to S6 in order and is finally imaged on the imaging surface S7.

Table 1 shows the surface type, radius of curvature, thickness, material, and conic coefficient of each lens of the iris lens in example 1.

Flour mark	Surface type	Radius of curvature	Thickness of	Material	Coefficient of cone
						OBJ	Spherical surface	All-round	260.0000
STO	Spherical surface	All-round	-0.3561
						S1	Aspherical surface	1.3231	0.9308	1.492/81.61	0.4593
S2	Aspherical surface	4.3707	1.7510		1.0000
						S3	Aspherical surface	-5.4140	0.4544	1.622/23.53	1.0000
S4	Aspherical surface	5.5684	0.1692		-63.9236
						S5	Spherical surface	All-round	0.2100	1.517/64.17
S6	Spherical surface	All-round	0.6000
						S7	Spherical surface	All-round

TABLE 1

In the embodiment, two lenses are taken as an example, and the focal length and the surface type of each lens are reasonably distributed, so that the total length of the lens is effectively shortened, and the relative illumination of the lens and the identification precision of the lens are improved; meanwhile, various aberrations are corrected, and the resolution and the imaging quality of the lens are improved. Each aspherical surface type x is defined by the following formula:

wherein x is a non-sphereWhen the surface is at the position with the height of h along the optical axis direction, the distance from the vertex of the aspheric surface is higher; 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 the conic coefficient (given in table 1 above); ai is the correction coefficient of the i-th order of the aspherical surface. Table 2 below shows the high-order term coefficients A that can be used for the aspherical mirror surfaces S1 to S4 in example 1₄、A₆、A₈、A₁₀、A₁₂、A₁₄And A₁₆。

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

-2.7825E-02

-2.3370E-02

4.0932E-02

-1.3584E-01

1.5653E-01

-8.2473E-02

0.0000E+00

S2

4.1007E-02

1.2926E-01

-4.3835E-01

1.1608E+00

-1.4200E+00

7.5082E-01

0.0000E+00

S3

-3.0579E-01

-7.7277E-01

4.4362E+00

-1.5260E+01

2.8847E+01

-2.9261E+01

1.2011E+01

S4

-2.2537E-01

-4.8696E-02

3.7403E-01

-8.0992E-01

8.8518E-01

-5.0706E-01

1.1906E-01

TABLE 2

Table 3 gives the total effective focal length f of the iris lens, the effective focal length f1 of the first lens L1, the effective focal length f2 of the second lens L2, the total optical length TTL of the iris lens (i.e., the distance on the optical axis from the object-side surface S1 of the first lens L1 to the imaging surface S7 of the iris lens), and half ImgH of the diagonal length of the effective pixel region of the electronic photosensitive element on the imaging surface S7 of the iris lens of embodiment 1.

Parameter(s)	f(mm)	f1(mm)	f2(mm)	TTL(mm)	ImgH(mm)
						Numerical value	4.30	3.50	-4.35	4.12	1.43

TABLE 3

From table 3, it can be seen that TTL/(ImgH ═ f) of the total optical length TTL of the iris lens, ImgH which is half the diagonal length of the effective pixel area of the electronic sensor on the image plane S7, and the total effective focal length f of the iris lens satisfy 0.67mm^-1. As can be seen from tables 1 and 3, the radius of curvature R4 of the image-side surface S4 of the second lens L2 and the total effective focal length f of the iris lens satisfy | R4/f | — 1.30; the first lens L1 and the second lens L2 satisfy T12/TTL of 0.43 between the separation distance T12 on the optical axis and the total optical length TTL of the iris lens.

In this embodiment, ET1/CT1 of the first lens L1 is 0.74 between the edge thickness ET1 and the central thickness CT1 of the first lens L1 on the optical axis; the effective radius DT11 of the object side surface S1 of the first lens L1 and the effective radius DT22 of the image side surface S4 of the second lens satisfy that DT11/DT22 is 0.80; the effective radius DT12 of the image side surface S2 of the first lens L1 and the effective radius DT22 of the image side surface S4 of the second lens satisfy DT12/DT22 ═ 0.72; the effective radius DT22 of the image side surface S4 of the second lens and the half of the diagonal length ImgH of the effective pixel area of the electronic photosensitive element on the image forming surface S7 meet the condition that DT22/ImgH is 0.79; the maximum thickness ET1max of the first lens L1 in the direction parallel to the optical axis and the minimum thickness ET1min of the first lens L1 in the direction parallel to the optical axis satisfy ET1max/ET1min of 1.20; the maximum incidence angle CRAmax of the chief ray on the electron photosensitive element is 24.14 °.

Fig. 2A shows an on-axis chromatic aberration curve of the iris lens of embodiment 1, which represents the deviation of the convergence focus of light rays of different wavelengths after passing through the iris lens. Fig. 2B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the iris lens of embodiment 1. Fig. 2C shows a distortion curve of the iris lens of embodiment 1, which represents the distortion magnitude values in the case of different viewing angles. Fig. 2D shows a chromatic aberration of magnification curve of the iris lens of embodiment 1, which represents a deviation of different image heights on an image plane after light passes through the iris lens. Fig. 2E shows a relative illuminance curve of the iris lens of embodiment 1, which represents the relative illuminance corresponding to different image heights on the image plane. As can be seen from fig. 2A to 2E, the iris lens according to embodiment 1 can achieve good imaging quality.

Example 2

An iris lens according to embodiment 2 of the present application is described below with reference to fig. 3 to 4E. 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 iris lens according to embodiment 2 of the present application.

As shown in fig. 3, the iris lens includes two lenses L1 and L2 arranged in order from the object side to the image side along the optical axis. A first lens L1 having an object-side surface S1 and an image-side surface S2; and a second lens L2 having an object-side surface S3 and an image-side surface S4. Optionally, the iris lens may further include a filter L3 having an object side S5 and an image side S6. The filter L3 may be an IR infrared filter with a bandpass band of about 785nm to about 835 nm. In the iris lens of the present embodiment, a stop STO for limiting a light beam may be further provided between the object side and the first lens L1 to improve the imaging quality. The light from the object passes through the respective surfaces S1 to S6 in order and is finally imaged on the imaging surface S7.

Table 4 shows the surface type, radius of curvature, thickness, material, and conic coefficient of each lens of the iris lens in example 2. Table 5 shows the high-order coefficient A of each aspherical mirror surface used in example 2₄、A₆、A₈、A₁₀、A₁₂、A₁₄And A₁₆. Table 6 shows the total effective focal length f of the iris lens, the effective focal length f1 of the first lens L1, the effective focal length f2 of the second lens L2, the optical total length TTL of the iris lens, and half of the diagonal length ImgH of the effective pixel region of the electro-photosensitive element on the imaging surface S7 of the iris lens of embodiment 2. Wherein each aspherical surface type can be defined by the formula (1) given in the above-described embodiment 1.

Flour mark	Surface type	Radius of curvature	Thickness of	Material	Coefficient of cone
						OBJ	Spherical surface	All-round	260.0000
STO	Spherical surface	All-round	-0.3582
						S1	Aspherical surface	1.3193	0.7814	1.537/56.11	0.5705
S2	Aspherical surface	3.7234	1.6091		-99.0000
						S3	Aspherical surface	-4.2966	0.4926	1.622/23.53	-14.7456
S4	Aspherical surface	11.5314	0.1064		1.0000
						S5	Spherical surface	All-round	0.2100	1.517/64.17
S6	Spherical surface	All-round	0.8749
						S7	Spherical surface	All-round

TABLE 4

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

-2.6160E-02

-9.8112E-02

3.2590E-01

-7.3463E-01

7.5777E-01

-3.2925E-01

0.0000E+00

S2

2.6250E-01

-5.4990E-01

1.2654E+00

-1.7467E+00

1.3458E+00

-3.6374E-01

0.0000E+00

S3

-3.3351E-01

-2.7563E-01

4.8402E-01

-4.3714E-01

-1.9811E+00

3.7155E+00

-2.4914E+00

S4

-2.0495E-01

-7.0167E-02

2.8496E-01

-4.8863E-01

4.2976E-01

-2.0449E-01

4.1370E-02

TABLE 5

Parameter(s)	f(mm)	f1(mm)	f2(mm)	TTL(mm)	ImgH(mm)
						Numerical value	4.30	3.42	-4.98	4.07	1.43

TABLE 6

Fig. 4A shows an on-axis chromatic aberration curve of the iris lens of embodiment 2, which represents the deviation of the convergence focus of light rays of different wavelengths after passing through the iris lens. Fig. 4B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the iris lens of embodiment 2. Fig. 4C shows a distortion curve of the iris lens of embodiment 2, which represents the distortion magnitude values in the case of different viewing angles. Fig. 4D shows a chromatic aberration of magnification curve of the iris lens of embodiment 2, which represents a deviation of different image heights on the image plane after the light passes through the iris lens. Fig. 4E shows a relative illuminance curve of the iris lens of embodiment 2, which represents the relative illuminance corresponding to different image heights on the image plane. As can be seen from fig. 4A to 4E, the iris lens according to embodiment 2 can achieve good imaging quality.

Example 3

An iris lens according to embodiment 3 of the present application is described below with reference to fig. 5 to 6E.

Fig. 5 shows a schematic structural diagram of an iris lens according to embodiment 3 of the present application.

As shown in fig. 5, the iris lens includes two lenses L1 and L2 arranged in order from the object side to the image side along the optical axis. A first lens L1 having an object-side surface S1 and an image-side surface S2; and a second lens L2 having an object-side surface S3 and an image-side surface S4. Optionally, the iris lens may further include a filter L3 having an object side S5 and an image side S6. The filter L3 may be an IR infrared filter having a bandpass band of about 785nm to about 835 nm. In the iris lens of the present embodiment, a stop STO for limiting a light beam may be further provided between the object side and the first lens L1 to improve the imaging quality. The light from the object passes through the respective surfaces S1 to S6 in order and is finally imaged on the imaging surface S7.

Table 7 shows the surface type, radius of curvature, thickness, material, and conic coefficient of each lens of the iris lens in example 3. Table 8 shows the high-order coefficient A which can be used for each aspherical mirror surface in example 3₄、A₆、A₈、A₁₀、A₁₂、A₁₄And A₁₆. Table 9 gives the total effective focal length f of the iris lens, the effective focal length f1 of the first lens L1, the effective focal length f2 of the second lens L2, the optical total length TTL of the iris lens, and half of the diagonal length ImgH of the effective pixel region of the electronic photoreceptor on the imaging surface S7 of the iris lens of embodiment 3. Wherein each aspherical surface type can be defined by the formula (1) given in the above-described embodiment 1.

TABLE 7

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

-4.7633E-02

-1.5765E-01

9.3141E-01

-4.1530E+00

9.2021E+00

-1.0447E+01

4.5212E+00

S2

6.1085E-01

-2.3867E+00

9.6314E+00

-2.8191E+01

5.7935E+01

-7.1768E+01

4.0952E+01

S3

-1.5086E+00

2.0247E+00

1.7414E-01

-4.1911E+01

1.6557E+02

-2.9444E+02

1.9063E+02

S4

-4.4143E-01

-1.6215E-01

2.5326E+00

-9.6285E+00

1.8539E+01

-1.8475E+01

7.5187E+00

TABLE 8

Parameter(s)	f(mm)	f1(mm)	f2(mm)	TTL(mm)	ImgH(mm)
						Numerical value	4.30	2.90	-3.35	3.66	1.40

TABLE 9

Fig. 6A shows an on-axis chromatic aberration curve of the iris lens of embodiment 3, which represents the deviation of the convergence focus of light rays of different wavelengths after passing through the iris lens. Fig. 6B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the iris lens of embodiment 3. Fig. 6C shows a distortion curve of the iris lens of embodiment 3, which represents the distortion magnitude values in the case of different viewing angles. Fig. 6D shows a chromatic aberration of magnification curve of the iris lens of embodiment 3, which represents a deviation of different image heights on the image plane after the light passes through the iris lens. Fig. 6E shows a relative illuminance curve of the iris lens of embodiment 3, which represents the relative illuminance corresponding to different image heights on the image plane. As can be seen from fig. 6A to 6E, the iris lens according to embodiment 3 can achieve good imaging quality.

Example 4

An iris lens according to embodiment 4 of the present application is described below with reference to fig. 7 to 8E.

Fig. 7 shows a schematic structural diagram of an iris lens according to embodiment 4 of the present application.

As shown in fig. 7, the iris lens includes two lenses L1 and L2 arranged in order from the object side to the image side along the optical axis. A first lens L1 having an object side surface S1 and an image side surface S2; and a second lens L2 having an object-side surface S3 and an image-side surface S4. Optionally, the iris lens may further include a filter L3 having an object side S5 and an image side S6. The filter L3 may be an IR infrared filter with a bandpass band of about 785nm to about 835 nm. In the iris lens of the present embodiment, a stop STO for limiting a light beam may be further provided between the object side and the first lens L1 to improve the imaging quality. The light from the object passes through the respective surfaces S1 to S6 in order and is finally imaged on the imaging surface S7.

Table 10 shows the surface type, radius of curvature, thickness, material, and conic coefficient of each lens of the iris lens in example 4. Table 11 shows the high-order coefficient A which can be used for each aspherical mirror surface in example 4₄、A₆、A₈、A₁₀、A₁₂、A₁₄And A₁₆. Table 12 gives the total effective focal length f of the iris lens, the effective focal length f1 of the first lens L1, the effective focal length f2 of the second lens L2, the total optical length TTL of the iris lens, and half ImgH of the diagonal length of the effective pixel region of the electronic photosensitive element on the imaging surface S7 of the iris lens of example 4. Wherein each aspheric surfaceThe profile can be defined by the formula (1) given in the above-described embodiment 1.

Flour mark	Surface type	Radius of curvature	Thickness of	Material	Coefficient of cone
						OBJ	Spherical surface	All-round	260.0000
STO	Spherical surface	All-round	-0.3389
						S1	Aspherical surface	0.9738	0.6113	1.537/56.11	0.2641
S2	Aspherical surface	1.6960	1.2992		-99.0000
						S3	Aspherical surface	187.0863	0.3000	1.622/23.53	1.0000
S4	Aspherical surface	2.7991	0.2747		-21.3055
						S5	Spherical surface	All-round	0.2100	1.517/64.17
S6	Spherical surface	All-round	0.9857
						S7	Spherical surface	Go to nothing

Watch 10

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

1.2370E-02

-4.5618E-01

2.8196E+00

-9.8281E+00

1.9081E+01

-1.9479E+01

8.1856E+00

S2

2.2084E+00

-1.8264E+01

1.2729E+02

-5.7248E+02

1.5904E+03

-2.4535E+03

1.6269E+03

S3

-4.9117E-01

-2.3555E+00

1.9208E+01

-9.0295E+01

2.3731E+02

-3.3491E+02

1.9467E+02

S4

-4.1747E-01

4.1254E-02

9.9817E-01

-4.0704E+00

7.8205E+00

-7.7140E+00

3.1000E+00

TABLE 11

Parameter(s)	f(mm)	f1(mm)	f2(mm)	TTL(mm)	ImgH(mm)
						Numerical value	4.30	3.29	-4.58	3.68	1.40

TABLE 12

Fig. 8A shows an on-axis chromatic aberration curve of the iris lens of embodiment 4, which represents the deviation of the convergence focus of light rays of different wavelengths after passing through the iris lens. Fig. 8B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the iris lens of example 4. Fig. 8C shows a distortion curve of the iris lens of embodiment 4, which represents the distortion magnitude values in the case of different viewing angles. Fig. 8D shows a chromatic aberration of magnification curve of the iris lens of embodiment 4, which represents a deviation of different image heights on the image plane after the light passes through the iris lens. Fig. 8E shows a relative illuminance curve of the iris lens of example 4, which represents the relative illuminance corresponding to different image heights on the image plane. As can be seen from fig. 8A to 8E, the iris lens according to embodiment 4 can achieve good imaging quality.

Example 5

An iris lens according to embodiment 5 of the present application is described below with reference to fig. 9 to 10E.

Fig. 9 is a schematic view showing a structure of an iris lens according to embodiment 4 of the present application.

As shown in fig. 9, the iris lens includes two lenses L1 and L2 arranged in order from the object side to the image side along the optical axis. A first lens L1 having an object-side surface S1 and an image-side surface S2; and a second lens L2 having an object-side surface S3 and an image-side surface S4. Optionally, the iris lens may further include a filter L3 having an object side S5 and an image side S6. The filter L3 may be an IR infrared filter having a bandpass band of about 785nm to about 835 nm. In the iris lens of the present embodiment, a stop STO for limiting a light beam may be further provided between the first lens L1 and the second lens L2 to improve the imaging quality. The light from the object passes through the respective surfaces S1 to S6 in order and is finally imaged on the imaging surface S7.

Table 13 shows the surface type, radius of curvature, thickness, material, and conic coefficient of each lens of the iris lens in example 5. Table 14 shows the high-order coefficient A which can be used for each aspherical mirror surface in example 5₄、A₆、A₈、A₁₀、A₁₂、A₁₄And A₁₆. Table 15 shows the total effective focal length f of the iris lens, the effective focal length f1 of the first lens L1, the effective focal length f2 of the second lens L2, the total optical length TTL of the iris lens, and half ImgH of the diagonal length of the effective pixel region of the electronic photosensitive element on the imaging surface S7 of the iris lens of example 5. Wherein each aspherical surface type can be defined by the formula (1) given in the above-described embodiment 1.

Watch 13

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

-2.2534E-02

-3.8220E-02

1.0513E-01

-2.5572E-01

2.6669E-01

-1.2275E-01

0.0000E+00

S2

5.2950E-02

2.1007E-01

-8.5353E-01

3.3212E+00

-5.9250E+00

4.7546E+00

0.0000E+00

S3

-3.8866E-01

-3.1806E+00

2.6058E+01

-1.2681E+02

3.4131E+02

-4.8881E+02

2.8285E+02

S4

-3.5154E-01

-1.3362E-01

1.4914E+00

-4.9150E+00

8.1112E+00

-6.9308E+00

2.4034E+00

TABLE 14

Parameter(s)	f(mm)	f1(mm)	f2(mm)	TTL(mm)	ImgH(mm)
						Numerical value	4.13	3.12	-4.40	3.73	1.43

Watch 15

Fig. 10A shows on-axis chromatic aberration curves of the iris lens of embodiment 5, which represent deviation of convergence focuses of light rays of different wavelengths after passing through the iris lens. Fig. 10B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the iris lens of example 5. Fig. 10C shows a distortion curve of the iris lens of example 5, which represents the distortion magnitude values in the case of different viewing angles. Fig. 10D shows a chromatic aberration of magnification curve of the iris lens of example 5, which represents a deviation of different image heights on the image plane after the light passes through the iris lens. Fig. 10E shows a relative illuminance curve of the iris lens of example 5, which represents the relative illuminance corresponding to different image heights on the image plane. As can be seen from fig. 10A to 10E, the iris lens according to embodiment 5 can achieve good imaging quality.

Example 6

An iris lens according to embodiment 6 of the present application is described below with reference to fig. 11 to 12E. Fig. 11 is a schematic structural diagram of an iris lens according to embodiment 4 of the present application.

As shown in fig. 11, the iris lens includes two lenses L1 and L2 arranged in order from the object side to the image side along the optical axis. A first lens L1 having an object-side surface S1 and an image-side surface S2; and a second lens L2 having an object-side surface S3 and an image-side surface S4. Optionally, the iris lens may further include a filter L3 having an object side S5 and an image side S6. The filter L3 may be an IR infrared filter having a bandpass band of about 785nm to about 835 nm. In the iris lens of the present embodiment, a stop STO for limiting a light beam may be further provided between the first lens L1 and the second lens L2 to improve the imaging quality. The light from the object passes through the respective surfaces S1 to S6 in order and is finally imaged on the imaging surface S7.

Table 16 shows the surface type, radius of curvature, thickness, material, and conic coefficient of each lens of the iris lens in example 6. Table 17 shows the high-order coefficient A which can be used for each aspherical mirror surface in example 6₄、A₆、A₈、A₁₀、A₁₂、A₁₄And A₁₆. Table 18 gives the total effective focal length f of the iris lens, the effective focal length f1 of the first lens L1, the effective focal length f2 of the second lens L2, the total optical length TTL of the iris lens, and half ImgH of the diagonal length of the effective pixel region of the electronic photosensitive element on the imaging surface S7 of the iris lens of example 6. Wherein each aspherical surface type can be defined by formula (1) given in embodiment 1 above.

Flour mark	Surface type	Radius of curvature	Thickness of	Material	Coefficient of cone
						OBJ	Spherical surface	Go to nothing	260.0000
S1	Aspherical surface	1.0977	0.8187	1.537/56.11	0.1520
						S2	Aspherical surface	2.2950	0.3290		0.9960
STO	Spherical surface	Go to nothing	0.8960
						S3	Aspherical surface	-3.0685	0.3580	1.622/23.53	0.4223
S4	Aspherical surface	-123.0086	0.3765		-3.1327
						S5	Spherical surface	All-round	0.2100	1.517/64.17
S6	Spherical surface	Go to nothing	0.7433
						S7	Spherical surface	Go to nothing

TABLE 16

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

-1.9164E-02

-2.7257E-02

7.4036E-02

-1.8945E-01

2.0138E-01

-9.5530E-02

0.0000E+00

S2

6.8147E-02

1.6641E-01

-4.4392E-01

1.9723E+00

-3.7066E+00

3.6909E+00

0.0000E+00

S3

-3.5832E-01

-2.7831E+00

2.1916E+01

-1.0353E+02

2.6915E+02

-3.7250E+02

2.0669E+02

S4

-3.2472E-01

-2.1106E-01

1.6033E+00

-4.9099E+00

7.7491E+00

-6.4143E+00

2.1613E+00

TABLE 17

Parameter(s)	f(mm)	f1(mm)	f2(mm)	TTL(mm)	ImgH(mm)
						Numerical value	4.06	3.16	-5.07	3.73	1.43

Watch 18

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

In summary, examples 1 to 6 each satisfy the relationship shown in table 19 below.

Conditional expression (A) example	1	2	3	4	5	6
							T12/TTL	0.43	0.39	0.37	0.35	0.35	0.33
DT11/DT22	0.80	0.86	0.95	0.91	0.99	0.97
							ET1max/ET1min	1.20	1.27	1.40	1.10	1.20	1.13
CRAmax(°)	24.14	24.31	27.92	28.84	29.03	28.93
							ET1/CT1	0.74	0.67	0.58	0.67	0.53	0.60
TTL/(ImgH*f)(mm-1)	0.67	0.66	0.61	0.61	0.63	0.64
							DT12/DT22	0.72	0.77	0.86	0.75	0.78	0.73
DT22/ImgH	0.79	0.76	0.56	0.58	0.65	0.64
							|R4/f|	1.30	2.68	2.98	0.65	14.38	30.29
R2/f1	1.25	1.09	0.91	0.52	0.81	0.73

Watch 19

The present application also provides an image pickup apparatus, the photosensitive element of which may be a photosensitive coupling 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 iris 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 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 (20)

1. The iris lens comprises a first lens and a second lens from an object side to an image side along an optical axis in sequence, the total number of the lenses with focal power in the iris lens is two,

it is characterized in that the preparation method is characterized in that,

the first lens has positive focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface;

the second lens has a negative optical power,

the distance T12 between the first lens and the second lens on the optical axis and the distance TTL between the object side surface of the first lens and the imaging surface of the iris lens on the optical axis satisfy T12/TTL >0.32,

an edge thickness ET1 of the first lens and a center thickness CT1 of the first lens on the optical axis satisfy 0.5< ET1/CT1<1, and

the iris lens further comprises an IR (infrared) filter arranged between the second lens and the imaging surface of the iris lens.

2. The iris lens as claimed in claim 1, wherein an effective radius DT11 of an object side surface of the first lens and an effective radius DT22 of an image side surface of the second lens satisfy 0.7< DT11/DT22 <1.

3. The iris lens as claimed in claim 1, wherein a maximum thickness ET1max of the first lens in a direction parallel to the optical axis and a minimum thickness ET1min of the first lens in a direction parallel to the optical axis satisfy 1< ET1max/ET1min < 1.45.

4. The iris lens as claimed in claim 1, further comprising an electro-photosensitive element disposed on an imaging surface of the iris lens,

the maximum incidence angle CRAmax of the main ray incident on the electronic photosensitive element satisfies CRAmax <30 degrees.

5. The iris lens as claimed in claim 1, wherein the band pass band of the IR infrared filter is 785nm to 835 nm.

6. An iris lens as claimed in claim 1, wherein 0.4mm^-1<TTL/(ImgH*f)<0.7mm^-1，

Wherein, TTL is the distance between the object side surface of the first lens and the imaging surface of the iris lens on the optical axis;

ImgH is half of the diagonal length of the effective pixel area of the electronic photosensitive element on the imaging surface of the iris lens;

f is the total effective focal length of the iris lens.

7. The iris lens as claimed in claim 1, wherein an effective radius DT12 of an image-side surface of the first lens and an effective radius DT22 of an image-side surface of the second lens satisfy 0.7< DT12/DT22 <1.

8. The iris lens as claimed in claim 1, wherein an effective radius DT22 of the image side surface of the second lens and a half ImgH of a diagonal length of an effective pixel area of an electron-sensitive element on an imaging surface of the iris lens satisfy 0.5< DT22/ImgH <1.

9. An iris lens as claimed in any one of claims 1 to 8, further comprising an aperture stop disposed between the object side and the first lens,

the curvature radius R4 of the image side surface of the second lens and the total effective focal length f of the iris lens meet | R4/f | < 3.

10. An iris lens as claimed in any one of claims 1 to 8, further comprising an aperture stop disposed between the first lens and the second lens,

a radius of curvature of an image-side surface of the first lens, R2, and an effective focal length f1 of the first lens satisfy 0.5< R2/f1< 0.9.

11. The iris lens comprises a first lens and a second lens from an object side to an image side along an optical axis in sequence, the total number of the lenses with focal power in the iris lens is two,

it is characterized in that the preparation method is characterized in that,

the first lens has positive focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface;

the second lens has a negative optical power,

an effective radius DT11 of the object side surface of the first lens and an effective radius DT22 of the image side surface of the second lens satisfy 0.7< DT11/DT22<1,

an edge thickness ET1 of the first lens and a center thickness CT1 of the first lens on the optical axis satisfy 0.5< ET1/CT1<1, and

the iris lens further comprises an IR (infrared) filter arranged between the second lens and the imaging surface of the iris lens.

12. An iris lens as claimed in claim 11, wherein a maximum thickness ET1max of the first lens in a direction parallel to the optical axis and a minimum thickness ET1min of the first lens in a direction parallel to the optical axis satisfy 1< ET1max/ET1min < 1.45.

13. An iris lens as claimed in claim 11 or 12, wherein an effective radius DT12 of the image side surface of the first lens and an effective radius DT22 of the image side surface of the second lens satisfy 0.7< DT12/DT22 <1.

14. An iris lens as claimed in claim 11 or 12, wherein an effective radius DT22 of the image side surface of the second lens and a half ImgH of a diagonal length of an effective pixel region of an electron-sensitive element on the image plane of the iris lens satisfy 0.5< DT22/ImgH <1.

15. The iris lens as claimed in claim 12, wherein a distance T12 between the first and second lenses on the optical axis and a distance TTL between an object side surface of the first lens and an image plane of the iris lens on the optical axis satisfy T12/TTL > 0.32.

16. The iris lens as claimed in claim 11 or 12, further comprising an electron photosensitive element disposed on an imaging surface of the iris lens, wherein a maximum incident angle CRAmax of a principal ray incident on the electron photosensitive element satisfies CRAmax <30 °.

17. The iris lens as claimed in claim 11, wherein the band pass band of the IR infrared filter is 785nm to 835 nm.

18. An iris lens as claimed in claim 11 or 12, characterized in that, 0.4mm^-1<TTL/(ImgH*f)<0.7mm^-1，

Wherein, TTL is the distance between the object side surface of the first lens and the imaging surface of the iris lens on the optical axis;

ImgH is half of the diagonal length of the effective pixel area of the electronic photosensitive element on the imaging surface of the iris lens;

f is the total effective focal length of the iris lens.

19. An iris lens as claimed in claim 11 or 12, further comprising an aperture stop disposed between the object side and the first lens,

the curvature radius R4 of the image side surface of the second lens and the total effective focal length f of the iris lens meet | R4/f | < 3.

20. An iris lens as claimed in claim 11 or 12, further comprising an aperture stop disposed between the first lens and the second lens,

a radius of curvature of an image-side surface of the first lens, R2, and an effective focal length f1 of the first lens satisfy 0.5< R2/f1< 0.9.

Images