CN112462486B

CN112462486B - Optical lens

Info

Publication number: CN112462486B
Application number: CN201910842433.4A
Authority: CN
Inventors: 刘冰玉; 杜佳玮
Original assignee: Yuyao Sunny Optical Intelligence Technology Co Ltd
Current assignee: Yuyao Sunny Optical Intelligence Technology Co Ltd
Priority date: 2019-09-06
Filing date: 2019-09-06
Publication date: 2022-07-26
Anticipated expiration: 2039-09-06
Also published as: CN112462486A

Abstract

The present invention provides an optical lens, which includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element, wherein image side surfaces and object side surfaces of the first lens element, the second lens element, the third lens element and the fourth lens element are aspheric. In this way, the optical lens can be applied to optical sensors of various intelligent devices based on TOF technology, such as sweeping robots, laser radars, gesture recognition devices and the like, and meets the optical performance requirements of the optical sensors.

Description

Optical lens

Technical Field

The present invention relates to optical systems, and more particularly to wide-angle optical lenses for TOF smart devices.

Background

The diversification of intelligent equipment brings great convenience to the modern society, and the research and development of the intelligent equipment are more and more concerned by various fields. Among the sensors of the smart device, the most important is an optical sensor that collects a peripheral effective signal. Moreover, smart devices such as depth sensing devices (including but not limited to laser radar, sweeping robots, etc.) developed based on TOF modules are developing in the direction of mass production, miniaturization and civilian use.

Currently, TOF (Time of flight) ranging technology is widely applied to optical sensors of various intelligent devices such as gesture recognition, sweeping robots, and laser radars. In some practical applications, an optical sensor based on TOF ranging technology is used for detecting the surface depth information, and therefore, in these application scenarios, the optical sensor needs to be equipped with a wide-angle optical lens with a certain field angle, so as to observe the environmental depth characteristic information within a certain solid angle range. The existing optical lens is generally an optical lens based on linear TOF, and is difficult to meet application requirements.

Further, those skilled in the art will appreciate that the optical sensor is mainly designed to the optical lens according to the light sensing capability of the light sensing chip and the range measurement range. However, the pixel units of different photosensitive chips receive different light energies. Therefore, in order to ensure that the returned light in the test range can be received by the photosensitive chip to convert the pixel unit into an effective pixel, the entrance pupil of the optical sensor needs to be increased as much as possible to ensure the light receiving capability and the light passing amount of the optical lens (i.e., the optical lens should be configured as a wide-angle optical lens). In addition, the angular resolution of the wide-angle optical lens can meet the application requirements in consideration of the interpretation accuracy of the depth information. However, the optimization of the existing optical imaging system is difficult to satisfy the above requirements.

In addition, compared with the existing optical lens based on linear TOF, the wide-angle optical lens based on TOF ranging has a significantly larger maximum system information receiving angle under the same horizontal test angle. Meanwhile, in order to guarantee that no vignetting and balanced distortion relation exist, the wide-angle optical lens based on TOF ranging has higher design requirements and is more difficult to meet application requirements.

Disclosure of Invention

An object of the present invention is to provide an optical lens, wherein the optical lens can be applied to optical sensors of various intelligent devices based on TOF technology, such as sweeping robots, laser radars, etc., for detecting face depth information.

Another object of the present invention is to provide an optical lens capable of balancing the relationship between distortion and relative illumination, and tending to an optimized system balance point, and improving the relative illumination of the system.

Another objective of the present invention is to provide an optical lens, which can expand a view field, reduce coma aberration of a large view field light spot, improve light spot concentration of the large view field, and reduce a light spot size, so as to better match a CRA angle requirement of a chip, ensure that all signal lights under the whole view field can be effectively received and sensed, and improve the working performance of the wide-angle optical lens.

Another object of the present invention is to provide an optical lens, wherein the surface type of each lens of the wide-angle optical lens can be adjusted within a reasonable range, thereby ensuring processing feasibility, simultaneously correcting wavefront aberration of light more scientifically, effectively correcting curvature of field and astigmatism, and making the mirror surface matching between each lens more harmonious so as to reduce tolerance sensitivity.

Another object of the present invention is to provide an optical lens, wherein the amount of light passing through each field can be preset and adjusted to reduce the aberration caused by marginal rays while maintaining the relative illuminance without vignetting.

Another object of the present invention is to provide an optical lens, wherein the lenses of the wide-angle optical lens have a certain distance therebetween, so as to avoid the problems caused by the lens adhesion.

Another objective of the present invention is to provide an optical lens capable of controlling the direction of light to provide a certain light angle to compensate for the negative light angle.

Another object of the present invention is to provide an optical lens capable of balancing system diopter configuration, system distortion and aberration.

Another object of the present invention is to provide an optical lens having a simple structure and excellent parameter configuration, which meets the requirements for the interpretation accuracy of TOF depth information.

According to an aspect of the present invention, there is provided an optical lens including:

a first lens having a negative refractive power;

a second lens having positive optical power;

a third lens having a positive refractive power; and

and a fourth lens having positive refractive power, wherein the first, second, third, and fourth lenses are set to form an optical axis, and wherein surfaces of an image side and an object side of the first, second, third, and fourth lenses are aspheric.

In some embodiments, the focal length f1 of the first lens, the focal length f2 of the second lens, and the focal length f3 of the third lens satisfy: 12< | (f2+ f3)/f | < 17.5; and, 0.4< | (f1+ f3)/f | < 0.6.

In some embodiments, the optical lens further includes a stop disposed between the second lens and the third lens.

In some embodiments, the effective aperture D1 of the first lens and the aperture DS of the stop satisfy: 4< D1/DS < 5.5.

In some embodiments, any two adjacent ones of the first lens, the second lens, the third lens and the fourth lens have a certain distance therebetween.

In some embodiments, the first lens is made of a plastic material.

In some embodiments, a region of the object-side surface of the second lens element, which is closer to the optical axis, is convex, and a region of the image-side surface of the second lens element, which is closer to the optical axis, is concave.

In some embodiments, a region of an object-side surface of the third lens element, which is closer to the optical axis, is convex or concave, and a region of an image-side surface of the third lens element, which is closer to the optical axis, is convex.

In some embodiments, a region of an object-side surface of the fourth lens element, which is closer to the optical axis, is convex, and a region of an image-side surface of the fourth lens element, which is closer to the optical axis, is convex.

Further objects and advantages of the present application will become apparent from an understanding of the ensuing description and drawings.

These and other objects, features and advantages of the present application will become more fully apparent from the following detailed description, the accompanying drawings and the claims.

Drawings

Fig. 1 is a schematic structural view of an optical lens according to a first embodiment of a preferred embodiment of the present invention.

Fig. 2 is a relative illuminance diagram of the optical lens according to the first embodiment of the above preferred embodiment of the present invention.

Fig. 3 is an astigmatism diagram of an optical lens according to the first embodiment of the above preferred embodiment of the present invention.

Fig. 4 is a distortion diagram of an optical lens according to the first embodiment of the above preferred embodiment of the present invention.

Fig. 5 is a schematic structural view of an optical lens according to a second embodiment of the above preferred embodiment of the present invention.

Fig. 6 is a relative illuminance diagram of an optical lens according to the second embodiment of the above preferred embodiment of the present invention.

Fig. 7 is an astigmatism diagram of an optical lens according to a second embodiment of the above preferred embodiment of the present invention.

Fig. 8 is a distortion diagram of an optical lens according to a second embodiment of the above preferred embodiment of the present invention.

Fig. 9 is a schematic structural view of an optical lens according to a third embodiment of the above preferred embodiments of the present invention.

Fig. 10 is a relative illuminance diagram of an optical lens according to the third embodiment of the above preferred embodiment of the present invention.

Fig. 11 is an astigmatism diagram of an optical lens according to the third embodiment of the above preferred embodiments of the present invention.

Fig. 12 is a distortion diagram of an optical lens according to a third embodiment of the above-described preferred embodiment of the present invention.

Fig. 13 is a schematic structural view of an optical lens according to a fourth embodiment of the above preferred embodiments of the present invention.

Fig. 14 is a relative illuminance diagram of an optical lens according to the fourth embodiment of the above preferred embodiment of the present invention.

Fig. 15 is an astigmatism diagram of an optical lens according to the fourth embodiment of the above preferred embodiment of the present invention.

Fig. 16 is a distortion diagram of an optical lens according to a fourth embodiment of the above preferred embodiments of the present invention.

Fig. 17 is a schematic structural view of an optical lens according to a fifth embodiment of the above preferred embodiments of the present invention.

Fig. 18 is a relative illuminance diagram of an optical lens according to the fifth embodiment of the above preferred embodiment of the present invention.

Fig. 19 is an astigmatism diagram of an optical lens according to the fifth embodiment of the above preferred embodiments of the present invention.

Fig. 20 is a distortion diagram of an optical lens according to a fifth embodiment of the above-described preferred embodiment of the present invention.

Fig. 21 is a schematic structural view of an optical lens according to a sixth embodiment of the above preferred embodiments of the present invention.

Fig. 22 is a relative illuminance diagram of an optical lens according to the sixth embodiment of the above preferred embodiment of the present invention.

Fig. 23 is an astigmatism diagram of an optical lens according to the sixth embodiment of the above preferred embodiment of the present invention.

Fig. 24 is a distortion diagram of an optical lens according to the sixth embodiment of the above preferred embodiment of the present invention.

Detailed Description

The following description is provided to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The underlying principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the invention and simplicity in description, but do not indicate or imply that the device or component being referred to must have a particular orientation, be constructed in a particular orientation, and be constructed in a particular manner of operation, and thus, the terms are not to be construed as limiting the invention.

It is understood that the terms "a" and "an" should be interpreted as meaning that a number of one element or element is one in one embodiment, while a number of other elements is one in another embodiment, and the terms "a" and "an" should not be interpreted as limiting the number.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.

Exemplary optical lens

As shown in fig. 1 to 24, an optical lens according to a preferred embodiment of the present invention is illustrated, wherein the optical lens 100 can be applied to optical sensors of various intelligent devices based on TOF technology, such as a sweeping robot, a laser radar, a gesture recognition device, etc., for detecting face depth information. Compared with the conventional optical lens based on linear TOF, the optical lens of the present invention has a larger field angle, and therefore, for convenience of distinction and explanation, in the embodiment of the invention, the optical lens 100 is defined as a wide-angle optical lens 100.

In the preferred embodiment of the present invention, the wide-angle optical lens 100, in order from an object side to an image side, comprises: a first lens element 10, a second lens element 20, a third lens element 30 and a fourth lens element 40, wherein the first lens element 10, the second lens element 20, the third lens element 30 and the fourth lens element 40 are all located on the same optical axis. In particular, in the preferred embodiment of the present invention, the fourth lens 40 is adjacent to a photosensitive chip to define an image side, and the first lens 10 is away from the fourth lens 40 to define an object side, wherein when the wide-angle optical lens 100 is applied to capture an image of a target object, the first lens 10 is closest to the target object, and imaging light passes through the first lens 10, the second lens 20, the third lens 30 and the fourth lens 40 in sequence and is received by the photosensitive chip.

In particular, in this preferred embodiment of the present invention, the first lens 10 has a negative optical power, the second lens 20 has a positive optical power, the third lens 30 has a positive optical power, and the fourth lens 40 has a positive optical power. Also, the image side surfaces and the object side surfaces of the first, second, third, and fourth lenses are all aspheric (here, it is understood that the image side surfaces of the lenses represent surfaces facing the image side, and the object side surfaces thereof represent surfaces facing the object side).

In particular, in the preferred embodiment of the present application, the first lens 10, the second lens 20, the third lens 30 and the fourth lens 40 are all non-cemented lenses, that is, in the preferred embodiment of the present application, any adjacent two of the first lens 10, the second lens 20, the third lens 30 and the fourth lens 40 have a certain distance therebetween, so as to avoid the problem caused by cemented lenses. Further, a focal length f (effective focal length f) of the wide-angle optical lens 10, a focal length f1 of the first lens 10, a focal length f2 of the second lens 20, a focal length f3 of the third lens 30, and a focal length f4 of the fourth lens 40 satisfy the following conditions:

10<|f2/f|<15

12< | (f2+ f3)/f | < 17.5; and

0.4<|(f1+f3)/f|<0.6。

thus, the overall length of the wide-angle optical lens 10 can be reduced to meet the demand of miniaturized applications; the third lens 30 provides the main diopter of the system, and the first lens 10 and the second lens 20 with weaker diopter are configured, so that the view field is enlarged, the coma aberration of the light spots in the large view field is reduced, the light spot concentration ratio in the large view field is improved, the size of the light spots is reduced, the CRA angle requirement of the chip is better matched, all signal lights in the whole view field can be effectively received and sensed, meanwhile, the working performance of the wide-angle optical lens 10 can be improved, the relation between distortion and relative illumination is balanced, and a system balance point tends to be optimized, so that the relative illumination of the system is improved.

In particular, in this preferred embodiment of the present application, the maximum sagittal height z7 of the image side surface S32 of the third lens 30, the maximum sagittal height z9 of the image side surface S42 of the fourth lens 40, parameters satisfy the following conditions:

2< | f/z7| < 4.5; and the number of the first and second groups,

2<|f/z9|<7。

therefore, on one hand, the surface shapes of the lenses of the wide-angle optical lens 100 can be preset and adjusted in a reasonable range, and the processing feasibility is ensured; on the other hand, the optical wavefront difference can be corrected more scientifically, and the curvature of field and astigmatism can be effectively corrected, so that the mirror surface matching between the lenses is more coordinated, and the tolerance sensitivity is reduced. In addition, can also alleviate the coma of big visual field facula, improve big visual field facula concentration degree, match the CRA angle demand of sensitization chip simultaneously, guarantee that light signal can be received effectively by sensitization chip, in order to improve wide angle optical lens 100's working property.

In particular, in the preferred embodiment of the present application, an effective aperture of the first lens 10 is D1, an aperture of the stop 50 between the image side of the second lens 20 and the object side of the third lens 30 is DS, and the following conditions are satisfied:

4<D1/DS<5.5。

in this way, the amount of light passing through each field of the wide-angle optical lens 100 can be preset and adjusted to reduce the aberration caused by marginal rays while maintaining the relative illuminance without vignetting.

In addition, in the preferred embodiment of the present application, the wide-angle optical lens 100 further includes a stop 50, wherein the stop 50 is located between the second lens 20 and the third lens 30 for limiting the amount of light entering. Preferably, the diaphragm 50 is implemented as a metal sheet having a light-passing hole, wherein the diaphragm 50 is generally circular, wherein the light-passing hole of the diaphragm 50 is centered on the optical axis of the wide-angle optical lens 100.

In addition, in the preferred embodiment of the present application, the wide-angle optical lens 100 further includes an optical filter 60, wherein the optical filter 60 is located between the fourth lens 40 and the chip, and is used for processing the imaging light. It should be noted that, in the embodiment of the present invention, the material and the shape structure of the filter 60 are not limited.

In addition, in the preferred embodiment of the present application, preferably, the first lens 10 is made of plastic or the like with a low refractive index, wherein the focal length f1 of the first lens 10 can be preset, so as to effectively control the matching relationship between the effective focal length of the wide-angle optical lens 100 and the distortion requirement of the chip for analyzing the optical signal, and adjust the focal length f of the wide-angle optical lens 100, thereby shortening the total length of the optical system to meet the miniaturization requirement.

In addition, in the preferred embodiment of the present application, the second lens element 20 is preferably made of a plastic material, wherein the object-side surface S21 of the second lens element 20 is convex at a paraxial region, and the image-side surface S22 of the second lens element 20 is concave at a paraxial region, so as to facilitate controlling a light direction and provide a certain light angle to compensate for the negative power of the first lens element 10. Here, the object-side surface S21 of the second lens element 20 represents a region of the object-side surface S21 of the second lens element 20 close to the optical axis at a paraxial region, and the image-side surface S22 of the second lens element 20 represents a region of the image-side surface S22 of the second lens element 20 close to the optical axis at a paraxial region.

In addition, in the preferred embodiment of the present application, preferably, the third lens element 30 is made of a plastic material, wherein the object-side surface S31 of the third lens element 30 is concave or convex at a paraxial region, and the image-side surface S32 of the third lens element 30 is convex at a paraxial region, wherein the third lens element 30 provides a main refractive power and can balance the refractive power configuration of the optical system to balance system distortion and aberration. Here, the object-side surface S31 of the third lens element 30 indicates a region of the object-side surface S31 of the third lens element 30 close to the optical axis at a paraxial region, and the image-side surface S32 of the third lens element 30 indicates a region of the image-side surface S32 of the third lens element 30 close to the optical axis at a paraxial region.

In addition, in the preferred embodiment of the present application, the fourth lens element 40 is preferably made of a plastic material, wherein the object-side surface S41 of the fourth lens element 40 is convex at a paraxial region, and the image-side surface S42 of the fourth lens element 40 is convex at a paraxial region, so as to adjust the wavefront of the emergent light beam and effectively correct the curvature of field and the astigmatism. Here, the object-side surface S41 of the fourth lens element 40 represents a region of the object-side surface S41 of the fourth lens element 40 near the optical axis at a paraxial region, and the image-side surface S42 of the fourth lens element 40 represents a region of the image-side surface S42 of the fourth lens element 40 near the optical axis at a paraxial region.

In the above, the wide-angle optical lens according to the embodiment of the present application is clarified, and can be applied to optical sensors of various intelligent devices based on TOF technology, such as a sweeping robot, a laser radar, a gesture recognition device, and the like, and meet optical performance requirements thereof.

Hereinafter, 6 specific groups of examples based on the preferred embodiment of the present invention are provided. It should be understood by those skilled in the art that the 6 sets of embodiments described below are merely exemplary and do not represent the only embodiments in which the preferred embodiments of the present invention can be implemented as the 6 sets of embodiments below.

Specifically, table 1 of parameter data of | f2/f |, | (f2+ f3)/f |, | (f1+ f3)/f |, | f/z7|, | f/z9|, and D1/DS in 6 sets of embodiments is as follows:

conditional formula (VII)	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6
							10<\|f2/f\|<15	10.71	10.68	10.21	14.95	10.09	10.07
12<\|(f2+f3)/f\|<17.5	12.84	12.79	12.46	17.03	12.28	12.17
							0.4<\|(f1+f3)/f\|<0.6	0.52	0.50	0.54	0.47	0.46	0.49
2<\|f/z7\|<4.5	3.00	2.73	3.22	3.82	2.67	4.13
							2<\|f/z9\|<7	4.25	4.02	7.18	7.28	6.32	2.55
4<D1/DS<5.5	5.15	4.52	5.82	4.64	5.17	4.01

TABLE 1

It should be understood that the parameter data of | f2/f |, | (f2+ f3)/f |, | (f1+ f3)/f |, | f/z7|, | f/z9| and D1/DS of the 6 embodiments shown in Table 1 are only used as 6 embodiments of the present invention, and are not intended to limit the present invention, that is, in other embodiments, the parameter data of | f2/f |, | (f2+ f3)/f |, | (f1+ f3)/f |, | f/z7|, | f/z9| and D1/DS may be changed within a reasonable range, respectively, and are not limited thereto.

Further, the aspherical surface curve equations of the first lens 10, the second lens 20, the third lens 30, and the fourth lens 40 are expressed as follows: x (Y) ═ Y ² /R)/(1+sqrt(1-(1+k)×(Y/R) ² ))+∑(A _i )×(Y ⁱ ) Wherein: x: the distance between the point on the aspheric surface and the optical axis is Y, and the distance is relative to the tangent plane of the intersection point on the aspheric surface optical axis; y: the vertical distance between a point on the aspheric curve and the optical axis; r: a radius of curvature; k: a cone coefficient; ai: the ith order aspheric coefficients.

Further, in the above embodiment 1, wherein the focal length of the wide-angle optical lens 100 is f, wherein the aperture value (f-number) of the wide-angle optical lens 100 is Fno, and half of the maximum angle of view in the wide-angle optical lens 100 is HFOV, wherein the parameter data are as follows: f 1.53mm, Fno 1.8, and HFOV 77 degrees. As shown in table 1 above, | f2/f | -10.71, | (f2+ f3)/f | -12.84, | (f1+ f3)/f | -0.52, | f/z7| -3.00, | f/z9| -4.25, and D1/DS | -5.15.

Specifically, the parameters of the curvature radius, thickness, material, refractive index, dispersion coefficient, and focal length of each element of the wide-angle optical lens 100 in the above-described embodiment 1 are given in table 2 below:

in table 2 above, the curvature radius, the thickness and the focal length are all in mm, the object-side surface of the first lens element 10 is S11, the image-side surface of the first lens element 10 is S12, the object-side surface of the second lens element 20 is S21, the image-side surface of the second lens element 20 is S22, the object-side surface of the third lens element 30 is S31, the image-side surface of the third lens element 30 is S32, the object-side surface of the fourth lens element 40 is S41, the image-side surface of the fourth lens element 40 is S42, the surface of the stop 50 is S5, the object-side surface of the filter 60 is S61, the image-side surface of the filter 60 is S62, and the image-side of the wide-angle optical lens 100 is S7.

Further, as shown in table 3, aspheric surface data in the above example 1 are shown:

in table 3, K represents the cone coefficients in the aspheric curve equation of each lens, and a4-a12 represents the 4 th to 12 th order aspheric coefficients of the object side surface and the image side surface of each lens.

Further, fig. 1, fig. 2, fig. 3 and fig. 4 are a group diagram, a relative illuminance diagram, an astigmatism diagram and a distortion diagram of the optical signal receiving wide-angle optical lens of the above embodiment 1 in this order.

Alternatively, in embodiment 2 of the present invention, wherein the focal length of the wide-angle optical lens 100 is f, the aperture value (f-number) of the wide-angle optical lens 100 is Fno, and half of the maximum viewing angle in the wide-angle optical lens 100 is HFOV, wherein the parameter data are as follows: f 1.53mm, Fno 1.6, and HFOV 77 degrees. As shown in table 1 above, | f2/f | -10.68, | (f2+ f3)/f | -12.79, | (f1+ f3)/f | -0.50, | f/z7| -2.73, | f/z9| -4.02, and D1/DS | -4.52.

Specifically, the parameters of the curvature radius, thickness, material, refractive index, dispersion coefficient, and focal length of each element of the wide-angle optical lens 100 in the above-described embodiment 2 are given in table 4 below:

wherein, in the above table 4, the unit of the curvature radius, the thickness and the focal length is mm.

Further, as shown in table 5, the aspherical surface data in the above example 2 is:

in table 5, K represents the cone coefficients in the aspheric curve equation for each lens, and a4-a12 represents the 4 th to 12 th order aspheric coefficients of the object-side surface and the image-side surface of each lens.

Further, fig. 5, 6, 7 and 8 are a diagram of the optical signal receiving wide-angle optical lens assembly, a relative illuminance diagram, an astigmatism diagram and a distortion diagram of the above-described embodiment 2 in this order.

Alternatively, in embodiment 3 of the present invention, wherein the focal length of the wide-angle optical lens 100 is f, the aperture value (f-number) of the wide-angle optical lens 100 is Fno, and half of the maximum viewing angle in the wide-angle optical lens 100 is HFOV, wherein the parameter data are as follows: f 1.58mm, Fno 1.8, and HFOV 77 degrees. As shown in table 1, i.e., | f2/f | -10.21, | (f2+ f3)/f | -12.46, | (f1+ f3)/f | -0.54, | f/z7| -3.22, | f/z9| -7.18, and D1/DS | -5.82.

Specifically, the parameters of the curvature radius, thickness, material, refractive index, dispersion coefficient, and focal length of each element of the wide-angle optical lens 100 in the above-described embodiment 3 are given in table 6 below:

wherein, in the above table 6, the unit of the curvature radius, the thickness and the focal length is mm.

Further, as shown in table 7, aspheric surface data in the above example 1 are shown:

in table 7, K represents the cone coefficients in the aspheric curve equation for each lens, and a4-a12 represents the 4 th to 12 th order aspheric coefficients of the object-side surface and the image-side surface of each lens.

Further, fig. 9, 10, 11 and 12 are a diagram of the optical signal receiving wide-angle optical lens assembly, a relative illuminance diagram, an astigmatism diagram and a distortion diagram of the above-described embodiment 3 in this order.

Optionally, in embodiment 4 of the present invention, wherein the focal length of the wide-angle optical lens 100 is f, the aperture value (f-number) of the wide-angle optical lens 100 is Fno, and half of the maximum viewing angle in the wide-angle optical lens 100 is HFOV, wherein the parameter data are as follows: f 1.53mm, Fno 1.65, and HFOV 77 degrees. As shown in table 1, 14.95, | f2/f |, | (f2+ f3)/f | -17.03, | (f1+ f3)/f | -0.47, | f/z7| -3.82, | f/z9| -7.28, and D1/DS | -4.64.

Specifically, the parameters of the radius of curvature, thickness, material, refractive index, dispersion coefficient, and focal length of each element of the wide-angle optical lens 100 in the above-described embodiment 4 are given in table 8 below:

in table 8 above, the unit of the curvature radius, the thickness and the focal length are all mm.

Further, as shown in table 9, the aspheric surface data in the above example 4:

in table 9, K represents the cone coefficients in the aspheric curve equation of each lens, and a4-a12 represents the aspheric coefficients of the 4 th to 12 th order on the object-side surface and the image-side surface of each lens.

Further, fig. 13, 14, 15 and 16 are a group diagram, a relative illuminance diagram, an astigmatism diagram and a distortion diagram of the optical signal receiving wide-angle optical lens of example 4 in this order.

Optionally, in embodiment 5 of the present invention, wherein the focal length of the wide-angle optical lens 100 is f, the aperture value (f-number) of the wide-angle optical lens 100 is Fno, and half of the maximum viewing angle in the wide-angle optical lens 100 is HFOV, wherein the parameter data are as follows: f 1.58mm, Fno 1.6, and HFOV 77 degrees. As shown in table 1, i.e., | f2/f | -10.09, | (f2+ f3)/f | -12.28, | (f1+ f3)/f | -0.46, | f/z7| -2.67, | f/z9| -6.32, and D1/DS | -5.17.

Specifically, the parameters of the curvature radius, thickness, material, refractive index, dispersion coefficient, and focal length of each element of the wide-angle optical lens 100 in the above-described embodiment 5 are given in table 10 below:

in table 10 above, the unit of the curvature radius, the thickness and the focal length are all mm.

Further, as shown in table 11, the aspheric surface data in the above example 5:

in table 11, K represents the cone coefficients in the aspheric curve equation for each lens, and a4-a12 represents the 4 th to 12 th order aspheric coefficients of the object-side surface and the image-side surface of each lens.

Further, fig. 17, fig. 18, fig. 19 and fig. 20 are a group diagram, a relative illuminance diagram, an astigmatism diagram and a distortion diagram of the optical signal receiving wide-angle optical lens of example 5.

Alternatively, in embodiment 6 of the present invention, wherein the focal length of the wide-angle optical lens 100 is f, the aperture value (f-number) of the wide-angle optical lens 100 is Fno, and half of the maximum viewing angle in the wide-angle optical lens 100 is HFOV, wherein the parameter data are as follows: f 1.53mm, Fno 1.45, and HFOV 77 degrees. As shown in table 1, i f2/f | ═ 10.07, | (f2+ f3)/f | 12.17, | (f1+ f3)/f | 0.49, | f/z7| 4.13, | f/z9| -2.55, and D1/DS | -4.01.

Specifically, the parameters of the radius of curvature, thickness, material, refractive index, dispersion coefficient, and focal length of each element of the wide-angle optical lens 100 in the above-described embodiment 6 are given in table 12 below:

in table 12 above, the unit of the curvature radius, the thickness and the focal length are all mm.

Further, as shown in table 13, the aspheric surface data in the above example 6:

in table 13, K represents the cone coefficients in the aspheric curve equation of each lens, and a4-a12 represents the aspheric coefficients of the 4 th to 12 th order on the object-side surface and the image-side surface of each lens.

Further, fig. 21, 22, 23 and 24 are a group diagram, a relative illuminance diagram, an astigmatism diagram and a distortion diagram of the optical signal receiving wide-angle optical lens of the above-mentioned embodiment 6 in this order.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are given by way of example only and are not limiting of the invention. The objects of the present invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the examples, and any variations or modifications of the embodiments of the present invention may be made without departing from the principles.

Claims

1. An optical lens is characterized in that the optical lens consists of a first lens with negative focal power, a second lens with positive focal power, a third lens with positive focal power and a fourth lens with positive focal power which are sequentially arranged from an object side to an image side, wherein the first lens, the second lens, the third lens and the fourth lens are set to form an optical axis, and the image side surfaces and the object side surfaces of the first lens, the second lens, the third lens and the fourth lens are aspheric;

wherein a focal length f of the optical lens, a focal length f1 of the first lens, a focal length f2 of the second lens, and a focal length f3 of the third lens satisfy:

12< | (f2+ f3)/f | < 17.5; and

0.4<|(f1+f3)/f|<0.6。

2. an optical lens according to claim 1, wherein a focal length f of the optical lens and a focal length f2 of the second lens satisfy:

10<|f2/f|<15。

3. the optical lens of claim 1, wherein a maximum sagittal height z7 of the image side surface of the third lens satisfies:

2<|f/z7|<4.5。

4. the optical lens of claim 3, wherein a maximum sagittal height z9 of the image side surface of the fourth lens satisfies:

2<|f/z9|<7。

5. an optical lens according to claim 1, further comprising a diaphragm disposed between the second lens and the third lens.

6. The optical lens of claim 5, wherein the effective aperture D1 of the first lens and the aperture DS of the stop satisfy:

4<D1/DS<5.5。

7. an optical lens according to claim 1, wherein any two adjacent ones of the first, second, third and fourth lenses have a spacing therebetween.

8. An optical lens according to claim 1, wherein the first lens is made of a plastic material.

9. The optical lens of claim 1, wherein a region of the object-side surface of the second lens element near the optical axis is convex, and a region of the image-side surface of the second lens element near the optical axis is concave.

10. The optical lens of claim 1, wherein a region of the object-side surface of the third lens element near the optical axis is convex or concave, and wherein a region of the image-side surface of the third lens element near the optical axis is convex.

11. The optical lens assembly as claimed in claim 1, wherein a region of the object-side surface of the fourth lens element near the optical axis is convex, and wherein a region of the image-side surface of the fourth lens element near the optical axis is convex.