CN111708147B

CN111708147B - 4p macro lens

Info

Publication number: CN111708147B
Application number: CN202010547793.4A
Authority: CN
Inventors: 王�锋; 孙加安; 周明明; 马庆鸿; 万良伟
Original assignee: Huizhou Xingjuyu Optical Co ltd
Current assignee: Guangdong Xingjuyu Optical Co ltd
Priority date: 2020-06-16
Filing date: 2020-06-16
Publication date: 2022-06-24
Anticipated expiration: 2040-06-16
Also published as: CN111708147A

Abstract

The invention provides a 4p macro lens, which, in order from an object side to an image side, comprises: a first lens, a second lens, a third lens and a fourth lens; the object side surface of the third lens is concave, and the object side surface of the fourth lens is concave; the distance between the object-side surface of the second lens element and the image-side surface of the fourth lens element on the optical axis is ZD, the focal length of the fourth lens element is f4, and the following relations are satisfied: ZD/f4= 0.256. The invention has the beneficial effects that: the micro-lens can be used as a secondary macro lens in double-shot or multi-shot, and the imaging effect is optimized on the basis of conventional macro shooting; the focal length is increased, so that the effect similar to a microscope is generated when the macro is shot.

Description

4p macro lens

Technical Field

The invention relates to the technical field of optical lenses, in particular to a 4p macro lens.

Background

In recent years, with the rise of smart phones, the demand of miniaturized camera lenses is gradually increasing, and the photosensitive devices of general camera lenses are not limited to two types, namely, a Charge Coupled Device (CCD) or a Complementary Metal-oxide semiconductor (CMOS) Sensor, and due to the advanced semiconductor manufacturing process technology, the pixel size of the photosensitive devices is reduced, and in addition, the current electronic products are developed in a form of being excellent in function, light, thin, short and small, so that the miniaturized camera lenses with good imaging quality are the mainstream in the current market.

In the related art, the current macro lens has poor imaging effect and small focal length, and cannot generate the effect similar to a microscope.

Disclosure of Invention

Based on this, it is necessary to design a 4p macro lens, which can solve the technical problems involved in the background art.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a 4p macro lens, the 4p macro lens comprising, in order from an object side to an image side: a first lens, a second lens, a third lens and a fourth lens;

the object side surface of the third lens is concave, and the object side surface of the fourth lens is concave;

the distance between the object-side surface of the second lens element and the image-side surface of the fourth lens element on the optical axis is ZD, the focal length of the fourth lens element is f4, and the following relations are satisfied:

ZD/f4=0.256。

preferably, the maximum curved surface distance from the maximum effective radius position of the object-side surface of the first lens to the horizontal optical axis is YD11, the maximum curved surface distance from the maximum effective radius position of the image-side surface of the second lens to the horizontal optical axis is YD22, and the following relations are satisfied:

YD11-YD22=0.729mm。

preferably, the focal length of the 4p macro lens is f, the radius of curvature of the image side surface of the second lens is R22, and the following relation is satisfied:

f/R22=0.754。

preferably, the radius of curvature of the image-side surface of the second lens element is R22, the radius of curvature of the object-side surface of the fourth lens element is R41, and the following relationships are satisfied:

R22/R41=-20.069。

preferably, the center thickness of the second lens on the optical axis is CT2, the sum of the center thicknesses of the first lens to the fourth lens on the optical axis is Σ CT, and the following relationship is satisfied:

CT2/ΣCT=0.190。

preferably, the focal length of the 4p macro lens is f, the radius of curvature of the image-side surface of the first lens is R12, the radius of curvature of the image-side surface of the second lens is R22, and the following relations are satisfied:

f/|R12|+f/|R22|=0.981。

preferably, the distance between the vertical projection point of the maximum effective radius position of the object-side surface of the third lens on the horizontal optical axis and the intersection point of the object-side surface of the third lens and the optical axis is SAG31, the refractive index of the fourth lens is n4, and the following relational expression is satisfied:

SAG31*n4=0.096mm。

the invention has the beneficial effects that:

1. the micro-lens can be used as a secondary macro lens in double-shot or multi-shot, and the imaging effect is optimized on the basis of conventional macro shooting;

2. the focal length is increased, so that the effect similar to a microscope is generated when the macro is shot.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a 4p macro lens according to embodiment 1 of the present invention;

fig. 2 is a spherical aberration graph of the 4p macro lens of embodiment 1;

fig. 3 is a graph of astigmatism and distortion of the 4p macro lens of example 1;

fig. 4 is a graph of chromatic aberration of magnification of the 4p macro lens of embodiment 1.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, the present invention provides a 4p macro lens, including four lenses, specifically, the 4p macro lens, in order from an object side to an image side along an optical axis, includes: a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4.

The 4p macro lens of the present invention may include an optical imaging system composed of four lenses. That is, the 4p macro lens may be configured by the first lens L1 to the fourth lens L4. However, the 4p macro lens is not limited to including four lenses, but may include other constituent elements as necessary. For example, the 4p macro lens further includes an aperture that adjusts the amount of light. In addition, an optical filter and an image plane may be sequentially disposed on the image side surface close to the fourth lens, an image sensor is disposed on the image plane, the image sensor may be any of various image sensors in the prior art, that is, the image sensor converts the light image on the light sensing surface into an electrical signal in a proportional relationship with the light image by using a photoelectric conversion function of a photoelectric device, and the image sensor is a functional device that divides the light image on the light receiving surface into a plurality of small cells and converts the small cells into usable electrical signals, compared with a photosensitive element of a "point" light source such as a photodiode and a phototriode.

Therefore, light rays refracted by external things sequentially pass through the first lens to the fourth lens, then enter the image plane through the optical filter, and are converted into conductive electric signals through the image sensor on the image plane.

Further, the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are plastic lenses or glass lenses. The first lens L1 to the fourth lens L4 are four independent lenses, and a space is provided between every two adjacent lenses, that is, every two adjacent lenses are not joined to each other, but an air space is provided between every two adjacent lenses. Since the process of the bonded lens is more complicated than that of the independent and non-bonded lens, especially the bonding surface of the two lenses needs to have a curved surface with high accuracy so as to achieve high bonding degree when the two lenses are bonded, and poor bonding degree due to deviation may also occur during the bonding process, which affects the overall optical imaging quality, so that the 4p macro lens is designed into four independent and non-bonded lenses to improve the problems generated by the bonded lens.

Referring to fig. 1, the object-side surface of the third lens element is concave, and the object-side surface of the fourth lens element is concave; the distance between the object-side surface of the second lens element and the image-side surface of the fourth lens element on the optical axis is ZD, the focal length of the fourth lens element is f4, and the following relations are satisfied: ZD/f4= 0.256.

More specifically, the 4p macro lens includes, in order from the object side to the image side along the optical axis, four lenses L1-L4, where the first lens L1 has an object side surface S1 and an image side surface S2; the second lens L2 has an object-side surface S3 and an image-side surface S4; the third lens L3 has an object-side surface S5 and an image-side surface S6; the fourth lens L4 has an object-side surface S7 and an image-side surface S8. Optionally, the 4p macro lens may further include a filter L5 having an object side S9 and an image side S10, and the filter L5 may be a band pass filter. In the image pickup optical lens group of the present embodiment, a stop STO may also be provided to adjust the amount of light entering. The light from the object passes through the respective surfaces S1 to S8 in order and is finally imaged on the imaging surface S11.

Further, the maximum curved surface distance from the maximum effective radius position of the object-side surface of the first lens to the horizontal optical axis is YD11, the maximum curved surface distance from the maximum effective radius position of the image-side surface of the second lens to the horizontal optical axis is YD22, and the following relations are satisfied: YD11-YD22=0.729 mm.

Further, the focal length of the 4p macro lens is f, the curvature radius of the image side surface of the second lens is R22, and the following relation is satisfied: f/R22= 0.754.

Further, the radius of curvature of the image-side surface of the second lens is R22, the radius of curvature of the object-side surface of the fourth lens is R41, and the following relations are satisfied: R22/R41= -20.069.

Further, the central thickness of the second lens on the optical axis is CT2, the sum of the central thicknesses of the first lens to the fourth lens on the optical axis is Σ CT, and the following relation is satisfied: CT2/Σ CT = 0.190.

Further, the focal length of the 4p macro lens is f, the radius of curvature of the image-side surface of the first lens is R12, the radius of curvature of the image-side surface of the second lens is R22, and the following relations are satisfied: f/| R12| + f/| R22| = 0.981.

Further, the distance from the vertical projection point of the maximum effective radius position of the object side surface of the third lens on the horizontal optical axis to the intersection point of the object side surface of the third lens and the optical axis is SAG31, the refractive index of the fourth lens is n4, and the following relational expression is satisfied: SAG31 × n4=0.096 mm.

The 4p macro lens according to the above embodiment of the present invention may employ a plurality of lenses, for example, four lenses as described above. The optical power, the surface type, the on-axis distance and the like of each lens are reasonably distributed, so that the effective light passing diameter of the 4p macro lens can be effectively increased, the miniaturization of the lens is ensured, the imaging quality is improved, and the 4p macro lens is more favorable for production and processing. In the embodiment of the present invention, 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 a better curvature radius characteristic, has the advantages of improving distortion aberration and astigmatic aberration, and can make the field of view larger and more realistic. After the aspheric lens is adopted, the aberration generated in imaging can be eliminated as much as possible, so that the imaging quality is improved.

Specific examples of the 4p macro lens that can be applied to the above-described embodiments are further described below with reference to the drawings.

Example 1

A 4p macro lens according to embodiment 1 of the present invention is described below with reference to fig. 1 to 4. Fig. 1 shows a schematic structural diagram of a 4p macro lens according to embodiment 1 of the present invention.

As shown in fig. 1, the 4p macro lens includes, in order from the object side to the image side, four lenses L1-L4, a first lens L1 having an object side surface S1 and an image side surface S2; the second lens L2 has an object-side surface S3 and an image-side surface S4; the third lens L3 has an object-side surface S5 and an image-side surface S6; the fourth lens L4 has an object-side surface S7 and an image-side surface S8. Optionally, the 4p macro lens may further include a filter L5 having an object side S9 and an image side S10, and the filter L5 may be a band pass filter. In the 4p macro lens of the present embodiment, a stop STO may also be provided to adjust the amount of light entering. The light from the object passes through the respective surfaces S1 to S10 in order and is finally imaged on the imaging surface S11.

The effective focal length EFL, the full field angle FOV, the total optical length TTL, the aperture Fno, the surface type, the curvature radius, the thickness, the material and the conic coefficient of the 4p macro lens in example 1 are shown in table 1:

TABLE 1

As can be seen from table 1, OBJ denotes a light source; the distance between the object-side surface of the second lens element and the image-side surface of the fourth lens element on the optical axis is ZD, the focal length of the fourth lens element is f4, and the following relations are satisfied: ZD/f4= 0.256; the maximum curved surface distance from the maximum effective radius position of the object side surface of the first lens to the horizontal optical axis is YD11, the maximum curved surface distance from the maximum effective radius position of the image side surface of the second lens to the horizontal optical axis is YD22, and the following relational expressions are satisfied: YD11-YD22=0.729 mm; the central thickness of the second lens on the optical axis is CT2, the sum of the central thicknesses of the first lens to the fourth lens on the optical axis is Sigma CT, and the following relations are satisfied: CT2/Σ CT = 0.190; the distance from a vertical projection point of the maximum effective radius position of the object side surface of the third lens on a horizontal optical axis to the intersection point of the object side surface of the third lens and the optical axis is SAG31, the refractive index of the fourth lens is n4, and the following relational expression is satisfied: SAG31 × n4=0.096 mm.

In the embodiment, four lenses are taken as an example, and the focal power and the surface type of each lens are reasonably distributed, so that the aperture of the lens is effectively enlarged, the total length of the lens is shortened, and the effective light transmission diameter of the lens and the miniaturization of the lens are ensured; meanwhile, various aberrations are corrected, and the resolution and the imaging quality of the lens are improved. Each aspheric surface type x is defined by the following functional relationship:

the aspheric function relationship of the 4p macro lens is as follows:

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 the conic constant (given in table 1 above); ai is a correction coefficient of the i-n th order of the aspherical surface, and the high-order term coefficients A4, A6, A8, A10, A12, A14 and A16 of the respective lens surfaces S1-S8 are shown in Table 2:

TABLE 2

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

-4.1681214E-02

1.5266374E-01

-2.0350435E-01

1.7371521E-01

-1.0091301E-01

5.6318627E-02

-1.6222857E-02

S2

-7.7461971E-03

3.6112978E-01

-9.1181676E-01

1.0357665E+00

2.6188572E-01

-1.6009663E+00

9.1587249E-01

S3

2.3982508E-01

-6.3913458E-01

3.0457593E+00

-6.8152677E+00

3.7258618E+00

5.8884483E+00

-6.3756871E+00

S4

-1.3026605E-01

3.7129949E+00

-1.5285514E+01

2.9411150E+01

-1.4394127E+01

-2.5188410E+01

2.4922385E+01

S5

-5.6490280E-01

1.1415168E+00

-1.7907166E+00

1.3167490E+00

-4.2547512E-01

4.9665186E-02

2.2755351E-04

S6

-4.6448494E-01

4.7144753E-01

-4.4640264E-01

2.8009501E-01

-1.0310440E-01

1.1744158E-02

2.1393933E-03

S7

-1.0455397E+00

1.3063110E+00

-6.2282603E-01

8.9219808E-02

4.7393704E-03

3.2742147E-03

-1.2553079E-03

S8

-7.5738104E-01

8.4322648E-01

-3.7396476E-01

5.4403714E-02

7.1296801E-03

-3.5191004E-03

4.5215244E-04

As can be seen from tables 1 and 2, in this embodiment, the focal length of the 4p macro lens is f, the radius of curvature of the image-side surface of the second lens element is R22, and the following relationship is satisfied: f/R22= 0.754; the curvature radius of the image side surface of the second lens is R22, the curvature radius of the object side surface of the fourth lens is R41, and the following relational expression is satisfied: the radius of curvature of the image side surface of the R22/R41= -20.069 lens is R22, and the following relational expression is satisfied: f/| R12| + f/| R22| = 0.981.

Fig. 2 shows a spherical aberration curve of the 4p macro lens of embodiment 1, which shows that the light rays of different aperture angles U intersect the optical axis at different points and have different deviations from the position of the ideal image point. Fig. 3 shows astigmatism curves of the 4p macro lens of embodiment 1, which represent meridional field curvature and sagittal field curvature. Fig. 3 shows distortion curves of the 4p macro lens of embodiment 1, which represent distortion magnitude values in the case of different viewing angles. Fig. 4 shows a chromatic aberration of magnification curve of the 4p macro lens of embodiment 1, which represents the deviation of different image heights on the imaging plane after the light passes through the 4p macro lens. As can be seen from fig. 2 to 4, the 4p macro lens according to embodiment 1 can achieve good imaging quality.

The invention has the beneficial effects that:

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above embodiments only express a few embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A 4p macro lens, wherein the 4p macro lens comprises, in order from an object side to an image side: the lens comprises a first lens, a second lens, a third lens and a fourth lens;

the first lens is a biconvex positive lens;

the second lens is a double concave negative lens;

the third lens has positive refractive power, 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;

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

ZD/f4=0.256。

2. the 4p macro lens according to claim 1, wherein the maximum curved surface distance from the maximum effective radius position of the object-side surface of the first lens to the horizontal optical axis is YD11, the maximum curved surface distance from the maximum effective radius position of the image-side surface of the second lens to the horizontal optical axis is YD22, and the following relations are satisfied:

YD11-YD22=0.729mm。

3. the 4p macro lens according to claim 1, wherein the focal length of the 4p macro lens is f, the radius of curvature of the image side surface of the second lens is R22, and the following relation is satisfied:

f/R22=0.754。

4. the 4p macro lens according to claim 1, wherein the radius of curvature of the image side surface of the second lens is R22, the radius of curvature of the object side surface of the fourth lens is R41, and the following relations are satisfied:

R22/R41=-20.069。

5. the 4p macro lens according to claim 1, wherein the center thickness of the second lens on the optical axis is CT2, the sum of the center thicknesses of the first to fourth lenses on the optical axis is Σ CT, and the following relation is satisfied:

CT2/ΣCT=0.190。

6. the 4p macro-lens according to claim 1, wherein the focal length of the 4p macro-lens is f, the curvature radius of the image side surface of the first lens is R12, the curvature radius of the image side surface of the second lens is R22, and the following relations are satisfied:

f/|R12|+f/|R22|=0.981。

7. the 4p macro lens of claim 1, wherein the distance between the perpendicular projection point of the maximum effective radius position of the object-side surface of the third lens on the horizontal optical axis to the intersection point of the object-side surface of the third lens and the optical axis is SAG31, the refractive index of the fourth lens is n4, and the following relation is satisfied:

SAG31*n4=0.096mm。