CN113156611B

CN113156611B - Optical lens and imaging apparatus

Info

Publication number: CN113156611B
Application number: CN202110206200.2A
Authority: CN
Inventors: 王东方; 姚波; 谢前森
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2017-03-01
Filing date: 2017-03-01
Publication date: 2023-10-27
Anticipated expiration: 2037-03-01
Also published as: CN108535834A; CN113156611A; CN108535834B

Abstract

The application provides an optical lens and an imaging apparatus. The number of lenses with focal power in the optical lens is six, namely a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, wherein the first lens to the sixth lens are sequentially arranged from an object side to an image side along an optical axis, the object side of the first lens is a convex surface, and the image side is a concave surface; the object side surface of the second lens is a concave surface, and the image side surface is a convex surface; the third lens is a biconvex lens with positive focal power; the sixth lens element has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, and a convex object-side surface at a distance from the sixth lens element.

Description

Optical lens and imaging apparatus

Statement of divisional application

The application is a divisional application of China patent application with the application number 201710116963.1, which is filed on the 2017 03 month 01 day and has the application name of optical lens and imaging equipment.

Technical Field

The present application relates to the field of optical lenses and imaging devices.

Background

Imaging apparatuses, such as camera-mounted mobile apparatuses and digital still cameras, using, for example, charge Coupled Devices (CCDs) and Complementary Metal Oxide Semiconductors (CMOS) as solid-state imaging elements, are well known.

With the development of technology, the resolution of optical lenses is increasingly required. And for the lens working in outdoor environment such as a monitoring lens or a vehicle-mounted lens, the requirement for achieving such resolution is more severe. Because the working environment of the monitoring lens or the vehicle-mounted lens is changeable, the perfect resolution is required to be maintained in hot and high-temperature days and cold rainy and snowy days.

In particular, on-board front view lenses involve active safety, and the temperature effects on lens imaging, typically control of the back focus offset, are more stringent. Because the temperature has a larger influence on the performance parameters of the plastic lens and is easy to influence the imaging quality of the lens, the common vehicle-mounted front view lens generally does not contain the plastic lens, but adopts a glass lens, so that the weight of the lens is increased, and if the high resolution is achieved, the cost is greatly increased.

Meanwhile, the vehicle-mounted front view mirror is generally required to be seen far, a front long-distance azimuth object is detected, the corresponding lens focal length is long, but the lens view angle is limited, and the view angle of the lens is small. Therefore, the conventional vehicle-mounted front view mirror has a small field angle, and needs to be matched with a wide-angle lens with a large field angle range to enlarge the whole observation field of view, and the picture splicing is completed by combining software.

Accordingly, there is a need for an improved optical lens and imaging apparatus.

Disclosure of Invention

The present application has been made in view of the above-mentioned drawbacks and deficiencies of the prior art, and an object of the present application is to provide a novel and improved optical lens and imaging apparatus capable of maintaining good temperature performance while employing a plastic lens.

An object of the present application is to provide an optical lens and an imaging apparatus, which improve the problem that the resolution is greatly affected by temperature when using a plastic lens by a reasonable combination of the shape setting and the optical power setting of each lens, so that the optical lens has good temperature performance, and the cost and weight of the optical lens are reduced.

An object of the present application is to provide an optical lens and an imaging apparatus which achieve a large angle of view by shape setting of respective lenses, thereby enlarging an overall field of view.

An object of the present application is to provide an optical lens and an imaging apparatus, which achieve miniaturization of the optical lens by shape setting of the respective lenses.

According to an aspect of the present application, there is provided an optical lens, wherein the number of lenses having optical power is six, namely, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, which are arranged in order from an object side to an image side along an optical axis, wherein the first lens has negative optical power, an object side surface thereof is a convex surface, and an image side surface thereof is a concave surface; the second lens has negative focal power, the object side surface of the second lens is concave, and the image side surface of the second lens is convex; the third lens is a biconvex lens with positive focal power; the fifth lens is glued with the fourth lens; and the sixth lens element with positive refractive power has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, a convex object-side surface at a far-axis region, and a concave image-side surface at a far-axis region.

In the above optical lens, plastic lenses are arranged in the first lens to the sixth lens, and the number of the plastic lenses is less than or equal to 2.

In the above optical lens, the first lens and the sixth lens are aspherical lenses.

In the above optical lens, one or both of the second lens and the sixth lens is/are a plastic lens, and the plastic lens is/are an aspherical lens.

In the above optical lens, the fourth lens is a biconvex lens having positive optical power, and the fifth lens is a biconcave lens having negative optical power.

In the above optical lens, the fourth lens is a biconcave lens having negative optical power, and the fifth lens is a biconvex lens having positive optical power.

In the above optical lens, further comprising a stop, the stop being located between the third lens and the fourth lens.

In the optical lens, F6/F is more than or equal to 2.5 and less than or equal to 6.5, wherein F6 is the focal length of the sixth lens, and F is the whole group focal length value of the optical lens.

In the optical lens, the FOV is more than or equal to 85 degrees, wherein the FOV is the field angle of the optical lens.

In the optical lens, TTL/F is more than or equal to 4.5 and less than or equal to 7, wherein TTL is the optical length of the optical lens.

In the above optical lens, the third lens is made of a high refractive index low abbe number material.

According to another aspect of the present application, there is provided an optical lens, wherein the number of lenses having optical power is six, namely, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, which are arranged in order from an object side to an image side along an optical axis, wherein the first lens has negative optical power, an object side surface thereof is a convex surface, and an image side surface thereof is a concave surface; the second lens has negative focal power, the object side surface of the second lens is concave, and the image side surface of the second lens is convex; the third lens is a biconvex lens with positive focal power; the fifth lens is glued with the fourth lens; the sixth lens element with positive refractive power has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, a convex object-side surface at a far-axis region, and a concave image-side surface at a far-axis region; wherein, -7.5 is less than or equal to F2/F is less than or equal to-3.5, wherein F2 is the focal length of the second lens, and F is the whole set of focal length values of the optical lens.

In the above optical lens, the optical lens further includes a stop, the stop being located between the third lens and the fourth lens.

In the optical lens, F6/F is more than or equal to 2.5 and less than or equal to 6.5, wherein F6 is the focal length of the sixth lens.

According to another aspect of the present application, there is provided an imaging apparatus including the above-described optical lens and an imaging element for converting an optical image formed by the optical lens into an electrical signal.

The optical lens and the imaging device provided by the application can improve the optical performance of the lens by adopting the plastic lens, and the optical power of the plastic lens is set by the shape of the lens, so that the optical lens has better temperature performance and reduces the cost and weight by reasonably matching with the optical power of other lenses.

In addition, the optical lens and the imaging device provided by the application realize a large field angle and enlarge the whole observation field.

In addition, the optical lens and the imaging device provided by the application realize miniaturization of the lens.

Drawings

Fig. 1 illustrates a lens configuration of an optical lens according to a first embodiment of the present application;

fig. 2 illustrates a lens configuration of an optical lens according to a second embodiment of the present application;

fig. 3 illustrates a lens configuration of an optical lens according to a third embodiment of the present application;

fig. 4 illustrates a lens configuration of an optical lens according to a fourth embodiment of the present application;

fig. 5A is a schematic diagram showing an imaging effect of the optical lens in the first embodiment of the present application at normal temperature;

FIG. 5D is a schematic diagram illustrating an imaging effect of the optical lens in the first embodiment of the present application at a high temperature;

fig. 5B and 5C are schematic diagrams illustrating imaging effects of an optical lens of the prior art at a high temperature;

fig. 6 is a schematic block diagram of an image forming apparatus according to an embodiment of the present application.

Detailed Description

The following description is presented to enable any person skilled in the art to make and use the application. The preferred embodiments in the following description are by way of example only and other obvious variations will occur to those skilled in the art. The basic principles of the application 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 application.

The terms and words used in the following description and claims are not limited to literal meanings, but are used only by the inventors to enable a clear and consistent understanding of the application. It will be apparent to those skilled in the art, therefore, that the following description of the various embodiments of the application is provided for illustration only and not for the purpose of limiting the application as defined by the appended claims and their equivalents.

The terminology used herein is for the purpose of describing various embodiments only and is not intended to be limiting. As used herein, the singular is intended to include the plural as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, or groups thereof.

Terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art, provided that the terms are not defined differently. It is to be understood that terms defined in commonly used dictionaries have meanings that are consistent with the meaning of the terms in the prior art.

The application is described in further detail below with reference to the attached drawings and detailed description:

[ configuration of optical lens ]

According to an embodiment of the present application, an optical lens includes, in order from an object side to an image side: the first lens is a meniscus lens with negative 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 is a meniscus lens with negative focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the third lens is a biconvex lens with positive focal power; a fourth lens; a fifth lens cemented with the fourth lens; and a sixth lens having positive optical power.

Wherein the second lens is preferably an aspherical lens, and more preferably, the second lens may be an aspherical lens close to concentric circles.

Wherein the fourth lens and the fifth lens have optical powers opposite to each other. For example, when the fourth lens has positive power, the fifth lens has negative power, and when the fourth lens has negative power, the fifth lens has positive power. And, the fourth lens and the fifth lens glued to each other have concave-convex shapes opposite to each other. For example, when the fourth lens is a biconvex lens, the fifth lens is a biconcave lens, and when the fourth lens is a biconcave lens, the fifth lens is a biconvex lens.

The sixth lens element with a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region. Preferably, the object-side surface of the sixth lens element on the far-beam axis is convex, and the image-side surface of the far-beam axis is concave.

By the shape setting and the optical power setting of the above-described lenses, one or more plastic lenses can be employed in the first to sixth lenses, thereby ensuring good temperature performance while achieving good imaging quality by employing plastic lenses.

Preferably, in the optical lens according to the embodiment of the present application, the number of plastic lenses is two or less.

Preferably, in the above optical lens, the second lens and the sixth lens are aspherical lenses.

Preferably, in the above optical lens, one or both of the second lens and the sixth lens is or are plastic lenses. According to an embodiment of the present application, the second lens and the sixth lens are both plastic lenses, and the plastic lenses are aspheric. ,

preferably, the first to sixth lenses satisfy the following conditional expression (1):

-7.5≤F2/F≤-3.5 (1)

f2 is the focal length of the second lens and F is the entire set of focal length values of the optical lens.

Preferably, the first to sixth lenses satisfy the following conditional expression (2):

2.5≤F6/F≤6.5 (2)

f6 is the focal length of the sixth lens, and F is the entire set of focal length values of the optical lens.

In this way, the optical lens according to the embodiment of the application can adopt plastic lenses among a plurality of lenses, particularly when the optical lens is applied to a vehicle-mounted front view lens, the plasticization of a large extent can be realized, and the problems that the vehicle-mounted front view lens relates to active safety and cannot use the plastic lenses, so that the cost is reduced and the imaging quality cannot be improved are solved.

In the optical lens according to the embodiment of the application, although the plastic lens is used, the reasonable collocation of the optical power setting of the plastic lens and the optical power of other lenses improves the problem that the use of the plastic lens greatly influences the resolution by temperature by the shape setting of each lens, so that the optical lens has good temperature performance, and the cost and weight of the optical lens are reduced.

In the above optical lens, the first lens to the sixth lens satisfy the following conditional expression (3):

FOV≥85 (3)

where FOV is the field angle of the optical lens.

Thus, in the optical lens according to the embodiment of the present application, a large angle of view is realized, thereby enlarging the entire field of view. Therefore, when applied to the vehicle-mounted front view lens, since it is not necessary to fit a wide angle lens of a large angle of view range to expand the overall field of view, the lens cost of the driving assistance system using the vehicle-mounted front view lens can be further saved.

In the above optical lens, the first lens to the sixth lens satisfy the following conditional expression (4):

4.5≤TTL/F≤7 (4)

wherein TTL is the optical length of the optical lens, i.e. the distance from the object side outermost point of the first lens to the imaging focal plane.

Therefore, according to the embodiment of the present application, a miniaturized optical lens can be obtained.

Next, the first to sixth lenses in the optical lens according to the embodiment of the present application will be described in further detail.

In the optical lens according to the embodiment of the application, the first lens element has a meniscus shape protruding toward the object side, and the object side surface thereof is convex and the image side surface thereof is concave. The first lens is bent towards the object side, so that the incident angle of incident light on the attack surface is small, and more light can be collected to enter the optical system of the embodiment of the application. In addition, when being applied to on-vehicle front-view lens, the convex surface is favorable to adapting to the outdoor use of on-vehicle front-view lens. For example, the convex surface may facilitate the sliding of water droplets when in an environment such as a rainy day.

In the optical lens assembly according to an embodiment of the application, the second lens element has a meniscus shape protruding toward the image side, and an object-side surface thereof is concave and an image-side surface thereof is convex. Because the first lens of the optical lens is a diverging lens, the meniscus lens configuration using the second lens makes the off-axis ray profile relatively gentle, thereby making the ray transition smoothly to the rear. In addition, the second lens is an aspherical lens, and the aspherical surface of the second lens has certain correction on off-axis aberration. In addition, more preferably, the second lens can be an aspheric lens close to concentric circles, which is beneficial to design and processing of the lens and can reduce aspheric cost.

In the optical lens assembly according to an embodiment of the application, the third lens element is a biconvex lens element, and has a convex object-side surface and a convex image-side surface. The third lens is a converging lens, and the light is compressed to smoothly pass through the third lens, so that the system light flux is increased. In addition, the third lens is preferably made of a material with a high refractive index and a low abbe number to compensate for the on-axis aberration generated by the first lens and the second lens.

In the optical lens according to the embodiment of the application, the fourth lens and the fifth lens glued to each other can correct chromatic aberration themselves, and at the same time, the fourth lens and the fifth lens cooperate with each other, and on-axis spot monochromatic aberration can be compensated while compensating for residual chromatic aberration.

In the optical lens assembly according to the embodiment of the application, the sixth lens element has a meniscus shape protruding toward the object side, and is an aspheric lens element having a convex surface at a paraxial region object side and a concave surface at a paraxial region image side. The sixth lens is a positive lens, so that light is converged, and an aspheric surface is utilized to better compensate off-axis aberration. Preferably, the object-side surface of the far-beam axis of the sixth lens is also convex, and the image-side surface of the far-beam axis is also concave

In the above optical lens, further comprising a diaphragm. Preferably, the diaphragm is located between the third lens and the fourth lens, so as to facilitate effective beam-converging of light entering the optical system and reduce the aperture of the lens of the optical system. Of course, one skilled in the art will appreciate that the aperture could be located between any other discrete lenses.

Further, in the case where the optical lens according to the embodiment of the present application includes a stop, the fourth lens and the fifth lens cemented with each other are preferably disposed at positions close to the stop in consideration of balance of system aberration and rationality of structure.

And the third lens can compress light to be smoothly injected into the diaphragm, thereby being beneficial to increasing the aperture of the diaphragm and increasing the light quantity of the system. Further, the sixth lens can further reduce the aperture value FNO and increase the aperture of the system diaphragm.

In the optical lens according to the embodiment of the present application, when two plastic lenses are used, the two plastic lenses are the main factors affecting the back focus variation at different temperatures, thereby affecting the temperature performance. Therefore, emphasis is placed on limiting the powers of the two plastic lenses, such as the second lens and the sixth lens, in combination with the powers of the other glass lenses, so that the temperature performance of the entire optical system is improved.

Here, it will be understood by those skilled in the art that the optical lens according to the embodiment of the present application may be applied to other lens applications requiring light weight, low cost and improved temperature performance in addition to the front view lens for vehicles, and the embodiment of the present application is not intended to be limited in any way.

[ numerical example of optical lens ]

In the following, specific embodiments of an optical lens according to embodiments of the present application and numerical examples in which specific numerical values are applied to the respective embodiments will be described with reference to the drawings and tables.

Some lenses used in the examples have aspherical lens surfaces, and aspherical surface shapes are represented by the following expression (5):

wherein, when Z (h) is at the position of height h along the optical axis direction, the distance vector from the vertex of the aspheric surface is high.

c=1/r, r denotes the radius of curvature of the lens surface, k is the conic coefficient, A, B, C, D and E are higher order aspheric coefficients, E in the coefficients represents a scientific notation, e.g. E-05 denotes 10 ^-5 。

In addition, nd represents the refractive index, and Vd represents the abbe coefficient.

First embodiment

As shown in fig. 1, an optical lens according to a first embodiment of the present application includes, in order from an object side to an image side: a meniscus-shaped first lens L1 with negative optical power, having a first surface S1 protruding toward the object side and a second surface S2 recessed toward the image side, i.e., the object side surface S1 of the first lens L1 is convex and the image side surface S2 is concave; a meniscus-shaped second lens L2 with negative focal power, having a first surface S3 concave toward the object side and a second surface S4 convex toward the image side, i.e., the object side surface S3 of the second lens L2 is concave and the image side surface S4 is convex; a biconvex-shaped third lens L3 having positive optical power, having a first surface S5 protruding toward the object side and a second surface S6 protruding toward the image side; a diaphragm STO; a fourth lens L4 and a fifth lens L5 cemented with each other, wherein the fourth lens L4 has a biconcave shape with negative optical power, a first surface S8 concave to the object side and a second surface S9 concave to the image side, and the fifth lens L5 has a biconvex shape with positive optical power, a first surface S9 convex to the object side and a second surface S10 convex to the image side; a meniscus-shaped sixth lens L6 with positive power, having a first surface S11 convex to the object side and a second surface S12 concave to the image side; a planar lens L7 having a first surface S13 toward the object side and a second surface S14 toward the image side, typically a color filter; a planar lens L8 having a first surface S15 facing the object side and a second surface S16 facing the image side, typically a cover glass, for protecting the imaging surface; l9 has an imaging surface S17, typically a chip.

The lens data of the above lens are shown in the following table 1:

[ Table 1 ]

Surface of the body	Radius of curvature	Thickness of (L)	Nd	Vd
					1	10.7812	0.9583	1.77	49.61
2	3.3542	3.3542
					3	-3.7892	1.7969	1.49	53.00
4	-6.1202	0.1198
					5	6.7239	2.5156	1.90	33.00
6	-19.1067	0.8385
					STO	Infinite number of cases	0.3594
8	-10.1196	0.7298	1.85	23.30
					9	3.6489	2.4326	1.72	54.00
10	-8.6357	0.1216
					11	6.0815	1.4596	1.51	56.29
12	38.6782	1.1979
					13	Infinite number of cases	0.5500	1.52	64.21
14	Infinite number of cases	5.2301
					15	Infinite number of cases	0.4000	1.52	64.21
16	Infinite number of cases	0.1250
					IMA	Infinite number of cases

The first surfaces S3 and S4 of the second lens, and the conic coefficients k and higher order aspherical coefficients A, B, C, D and E of the first surfaces S11 and S12 of the sixth lens are shown in table 2 below.

[ Table 2 ]

In the optical lens according to the first embodiment of the present application, the relationship among the focal length F2 of the second lens, the focal length F6 of the sixth lens, the entire set of focal length values F of the optical lens, and the optical length TTL of the optical lens and the relationship therebetween are shown in table 3 below.

[ Table 3 ]

F2	-27.105869
		F6	13.826973
F	4.5791
		TTL	22.1893
F2/F	-5.9195
		F6/F	3.01958
TTL/F	4.845778

As can be seen from table 3 above, the optical lens according to the first embodiment of the present application satisfies the foregoing conditional expressions (1), (2) and (4), thereby achieving good temperature performance and miniaturization of the optical lens.

Second embodiment

As shown in fig. 2, an optical lens according to a second embodiment of the present application includes, in order from an object side to an image side: a meniscus-shaped first lens L1 with negative optical power, having a first surface S1 protruding toward the object side and a second surface S2 recessed toward the image side, i.e., the object side surface S1 of the first lens L1 is convex and the image side surface S2 is concave; a meniscus-shaped second lens L2 with negative focal power, having a first surface S3 concave toward the object side and a second surface S4 convex toward the image side, i.e., the object side surface S3 of the second lens L2 is concave and the image side surface S4 is convex; a biconvex-shaped third lens L3 having positive optical power, having a first surface S5 protruding toward the object side and a second surface S6 protruding toward the image side; a diaphragm STO; a fourth lens L4 and a fifth lens L5 cemented with each other, wherein the fourth lens L4 has a biconcave shape with negative optical power, a first surface S8 concave to the object side and a second surface S9 concave to the image side, and the fifth lens L5 has a biconvex shape with positive optical power, a first surface S9 convex to the object side and a second surface S10 convex to the image side; a meniscus-shaped sixth lens L6 with positive power, having a first surface S11 convex to the object side and a second surface S12 concave to the image side; a planar lens L7 having a first surface S13 toward the object side and a second surface S14 toward the image side, typically a color filter; a planar lens L8 having a first surface S15 facing the object side and a second surface S16 facing the image side, typically a cover glass, for protecting the imaging surface; l9 has an imaging surface S17, typically a chip.

The lens data of the above lens are shown in the following table 4:

[ Table 4 ]

Surface of the body	Radius of curvature	Thickness of (L)	Nd	Vd
					1	6.2839	0.7194	1.78	47.20
2	2.1307	2.5113
					3	-2.9641	1.7172	1.51	56.29
4	-5.4697	0.3077
					5	8.3262	1.8884	1.80	42.25
6	-7.8630	0.9426
					STO	Infinite number of cases	0.1798
8	-31.4196	0.5395	1.83	27.30
					9	3.4978	1.4388	1.73	54.67
10	-7.5613	0.0450
					11	4.5517	1.0997	1.51	56.29
12	12.8821	0.2823
					13	Infinite number of cases	0.5500	1.52	64.21
14	Infinite number of cases	3.1407
					15	Infinite number of cases	0.4000	1.52	64.20
16	Infinite number of cases	0.1250
					IMA	Infinite number of cases

The first surfaces S3 and S4 of the second lens, and the conic coefficients k and higher order aspherical coefficients A, B, C, D and E of the first surfaces S11 and S12 of the sixth lens are shown in table 5 below.

[ Table 5 ]

In the optical lens according to the second embodiment of the present application, the relationship among the focal length F2 of the second lens, the focal length F6 of the sixth lens, the entire set of focal length values F of the optical lens, and the optical length TTL of the optical lens and the relationship therebetween are shown in table 6 below.

[ Table 6 ]

F2	-16.4041
		F6	13.10486
F	2.59347
		TTL	15.8837
F2/F	-6.3251512
		F6/F	5.05302278
TTL/F	6.1244973

As can be seen from table 6 above, the optical lens according to the second embodiment of the present application satisfies the foregoing conditional expressions (1), (2) and (4), thereby achieving good temperature performance and miniaturization of the optical lens.

Third embodiment

As shown in fig. 3, an optical lens according to a third embodiment of the present application includes, in order from an object side to an image side: a meniscus-shaped first lens L1 with negative optical power, having a first surface S1 protruding toward the object side and a second surface S2 recessed toward the image side, i.e., the object side surface S1 of the first lens L1 is convex and the image side surface S2 is concave; a meniscus-shaped second lens L2 with negative focal power, having a first surface S3 concave toward the object side and a second surface S4 convex toward the image side, i.e., the object side surface S3 of the second lens L2 is concave and the image side surface S4 is convex; a biconvex-shaped third lens L3 having positive optical power, having a first surface S5 protruding toward the object side and a second surface S6 protruding toward the image side; a diaphragm STO; a fourth lens L4 and a fifth lens L5 cemented with each other, wherein the fourth lens L4 has a biconvex shape with positive optical power, a first surface S8 with convex object side and a second surface S9 with convex image side, and the fifth lens L5 has a biconcave shape with negative optical power, a first surface S9 with concave object side and a second surface S10 with concave image side; a meniscus-shaped sixth lens L6 with positive power, having a first surface S11 convex to the object side and a second surface S12 concave to the image side; a planar lens L7 having a first surface S13 toward the object side and a second surface S14 toward the image side, typically a color filter; a planar lens L8 having a first surface S15 facing the object side and a second surface S16 facing the image side, typically a cover glass, for protecting the imaging surface; l9 has an imaging surface S17, typically a chip.

The lens data of the above lens are shown in the following table 7:

[ Table 7 ]

Surface of the body	Radius of curvature	Thickness of (L)	Nd	Vd
					1	12.9441	1.1261	1.77	52.30
2	3.5424	4.9668
					3	-4.4869	2.0411	1.51	56.29
4	-8.4750	1.3105
					5	9.8538	2.9561	1.90	31.32
6	-15.0924	0.1402
					STO	Infinite number of cases	0.0000
8	16.4157	2.8154	1.74	49.00
					9	-3.5556	0.8446	1.85	23.79
10	84.4608	1.3826
					11	8.9959	1.7596	1.51	56.29
12	703.8399	1.4077
					13	Infinite number of cases	0.5500	1.52	64.21
14	Infinite number of cases	2.3238
					15	Infinite number of cases	0.4000	1.52	64.21
16	Infinite number of cases	0.1250
					IMA	Infinite number of cases

The first surfaces S3 and S4 of the second lens, and the conic coefficients k and higher order aspherical coefficients A, B, C, D and E of the first surfaces S11 and S12 of the sixth lens are shown in table 8 below.

[ Table 8 ]

In the optical lens according to the third embodiment of the present application, the relationship among the focal length F2 of the second lens, the focal length F6 of the sixth lens, the entire set of focal length values F of the optical lens, and the optical length TTL of the optical lens and the relationship therebetween are shown in table 6 below.

[ Table 9 ]

F2	-22.4484
		F6	17.71066
F	3.57312
		TTL	24.1495
F2/F	-6.2825866
		F6/F	4.95663622
TTL/F	6.7586591

As can be seen from table 9 above, the optical lens according to the third embodiment of the present application satisfies the foregoing conditional expressions (1), (2) and (4), thereby achieving good temperature performance and miniaturization of the optical lens.

Fourth embodiment

As shown in fig. 4, an optical lens according to a fourth embodiment of the present application includes, in order from an object side to an image side: a meniscus-shaped first lens L1 with negative optical power, having a first surface S1 protruding toward the object side and a second surface S2 recessed toward the image side, i.e., the object side surface S1 of the first lens L1 is convex and the image side surface S2 is concave; a meniscus-shaped second lens L2 with negative focal power, having a first surface S3 concave toward the object side and a second surface S4 convex toward the image side, i.e., the object side surface S3 of the second lens L2 is concave and the image side surface S4 is convex; a biconvex-shaped third lens L3 having positive optical power, having a first surface S5 protruding toward the object side and a second surface S6 protruding toward the image side; a diaphragm STO; a fourth lens L4 and a fifth lens L5 cemented with each other, wherein the fourth lens L4 has a biconcave shape with negative optical power, a first surface S8 concave to the object side and a second surface S9 concave to the image side, and the fifth lens L5 has a biconvex shape with positive optical power, a first surface S9 convex to the object side and a second surface S10 convex to the image side; a meniscus-shaped sixth lens L6 with positive power, having a first surface S11 convex to the object side and a second surface S12 concave to the image side; a planar lens L7 having a first surface S13 toward the object side and a second surface S14 toward the image side, typically a color filter; a planar lens L8 having a first surface S15 facing the object side and a second surface S16 facing the image side, typically a cover glass, for protecting the imaging surface; l9 has an imaging surface S17, typically a chip.

The lens data of the above lens are shown in the following table 10:

[ Table 10 ]

Surface of the body	Radius of curvature	Thickness of (L)	Nd	Vd
					1	10.2972	0.7701	1.77	49.61
2	2.2595	2.5472
					3	-2.4899	1.5124	1.51	56.29
4	-4.7141	0.6050
					5	9.2875	1.6365	1.80	42.25
6	-7.7862	1.2494
					STO	Infinite number of cases	0.1925
8	-19.2530	0.5776	1.85	23.79
					9	3.7713	1.4440	1.73	54.67
10	-7.5019	0.0481
					11	4.9678	1.0589	1.51	56.29
12	14.8198	0.7835
					13	Infinite number of cases	0.5500	1.52	64.21
14	Infinite number of cases	4.7603
					15	Infinite number of cases	0.4000	1.52	64.21
16	Infinite number of cases	0.1250
					IMA	Infinite number of cases

The first surfaces S3 and S4 of the second lens, and the conic coefficients k and higher order aspherical coefficients A, B, C, D and E of the first surfaces S11 and S12 of the sixth lens are shown in table 11 below.

[ Table 11 ]

In the optical lens according to the fourth embodiment of the present application, the relationship among the focal length F2 of the second lens, the focal length F6 of the sixth lens, the entire set of focal length values F of the optical lens, and the optical length TTL of the optical lens and the relationship therebetween are shown in table 12 below.

[ Table 12 ]

F2	-13.3468
		F6	14.02472
F	2.8346
		TTL	18.2606
F2/F	-4.7085363
		F6/F	4.94768927
TTL/F	6.44203768

As can be seen from table 12 above, the optical lens according to the fourth embodiment of the present application satisfies the foregoing conditional expressions (1), (2) and (4), thereby achieving good temperature performance and miniaturization of the optical lens.

Imaging effect

The dot graphs of fig. 5A to 5D show the condensed state of light rays of different wavelengths on the imaging surface. Generally, the larger the field angle is, the larger the aberration of the peripheral field position is, the weaker the light-gathering capability is, and the imaging quality is lowered from the center.

Fig. 5A shows a point-column diagram of the lens peripheral field-of-view position related to the optical lens of the first embodiment of the present application at normal temperature. As shown in fig. 5A, the diffuse spots are concentrated, and the light of each color can be well condensed, so that the imaging quality of the image is excellent, and the resolution is good.

As shown in fig. 5B, if 3 or more plastic aspherical lenses are used, the optimum image plane offset due to expansion of the plastic lens at high temperature is too large, and the dot patterns on the same peripheral imaging plane are shown. As shown in fig. 5B, the diffuse spots are dispersed, the condensing performance is poor in each color light, the imaging quality of the image is poor, and the resolution is low.

Fig. 5C corresponds to the effect that the optical lens with a smaller angle of view in the prior art can achieve at a high temperature. As shown in fig. 5C, the diffuse spots are more concentrated and the imaging quality of the image is still better.

Fig. 5D corresponds to the optical lens of the first embodiment of the present application, in which 2 plastic lenses are used, and the peripheral field position after enlarging the field angle can still achieve the following effects at high temperature. As shown in fig. 5D, the diffuse spots are more concentrated, and the imaging quality of the image is better.

In summary, according to the optical lens provided by the embodiment of the application, the optical performance of the lens can be improved by adopting the plastic lens, and the optical power of the plastic lens is set by the shape of the lens, so that the optical lens has better temperature performance and reduces the cost and weight by reasonably matching with the optical power of other lenses.

In addition, the optical lens provided by the embodiment of the application realizes a large field angle and enlarges the whole observation field.

In addition, the optical lens according to the embodiment of the application realizes miniaturization of the lens.

[ configuration of image Forming apparatus ]

According to another aspect of the embodiments of the present application, there is provided an imaging apparatus including an optical lens and an imaging element for converting an optical image formed by the optical lens into an electrical signal, the optical lens including, in order from an object side to an image side: the first lens is a meniscus lens with negative 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 is a meniscus lens with negative focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the third lens is a biconvex lens with positive focal power; a fourth lens; a fifth lens cemented with the fourth lens; and a sixth lens having positive optical power.

Fig. 6 is a schematic block diagram of an image forming apparatus according to an embodiment of the present application. As shown in fig. 6, an imaging apparatus 100 according to an embodiment of the present application includes an optical lens 101 and an imaging element 102. The optical lens 101 is used for collecting an optical image of a subject, and the imaging element 102 is used for converting the optical image collected by the optical lens 101 into an electrical signal.

In the above optical lens assembly, the paraxial object-side surface of the sixth lens element is convex, the paraxial image-side surface of the sixth lens element is concave, and the paraxial object-side surface of the sixth lens element is convex, and the paraxial image-side surface of the sixth lens element is concave.

In the above optical lens, plastic lenses are provided in the first to sixth lenses of the optical lens, and the number of plastic lenses is less than or equal to 2.

In the above optical lens, one or both of the second lens and the sixth lens is/are a plastic lens, and the plastic lens is/are an aspherical surface.

In the above-described imaging apparatus, the fourth lens is a biconvex lens having positive optical power, and the fifth lens is a biconcave lens having negative optical power.

In the above-described imaging apparatus, the fourth lens is a biconcave lens having negative optical power, and the fifth lens is a biconvex lens having positive optical power.

In the above-described imaging apparatus, the first lens to the sixth lens satisfy the following conditional expression (1):

-7.5≤F2/F≤-3.5 (1)

wherein F2 is the focal length of the second lens, and F is the focal length value of the whole set of optical lenses.

In the above optical lens, the first lens to the sixth lens satisfy the following conditional expression (2):

2.5≤F6/F≤6.5 (2)

wherein F6 is a focal length of the sixth lens, and F is a focal length value of the optical lens.

In the above-described imaging apparatus, the first lens to the sixth lens satisfy the following conditional expression (3):

FOV≥85 (3)

wherein FOV is the field angle of the optical lens.

In the above-described imaging apparatus, the first lens to the sixth lens satisfy the following conditional expression (4):

4.5≤TTL/F≤7 (4)

wherein TTL is the optical length of the optical lens.

In the above-described imaging apparatus, the third lens is made of a high refractive index low abbe number material.

Here, it will be understood by those skilled in the art that other details of the optical lens in the imaging apparatus according to the embodiment of the present application are the same as those described with respect to the optical lens according to the embodiment of the present application, and the numerical examples of the optical lenses of the first to fourth embodiments of the present application described above may be adopted, so that no retrospection is made in order to avoid redundancy.

According to the optical lens and the imaging device, the optical performance of the lens can be improved by adopting the plastic lens, and the optical power of the plastic lens is set by the shape of the lens, so that the optical lens has better temperature performance and reduces cost and weight by reasonably matching with the optical power of other lenses.

In addition, the optical lens and the imaging device realize a large field angle and enlarge the whole observation field.

Furthermore, the optical lens and the imaging apparatus according to the embodiments of the present application achieve miniaturization of the lens.

In the optical lens barrel and the imaging apparatus according to the embodiment of the present application, a lens having substantially no lens power may also be arranged. Accordingly, in addition to the first to sixth lenses described above, further lenses may be arranged. In this case, the optical lens and the imaging apparatus according to the embodiment of the present application may be configured with six or more lenses, and these lenses include additional lenses arranged in addition to the first lens to the sixth lens described above.

It will be appreciated by persons skilled in the art that the embodiments of the application described above and shown in the drawings are by way of example only and are not limiting. The objects of the present application have been fully and effectively achieved. The functional and structural principles of the present application have been shown and described in the examples and embodiments of the application may be modified or practiced without departing from such principles.

Claims

1. An optical lens in which the number of lenses having optical power is six, which are respectively a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, the first lens to the sixth lens being arranged in order from an object side to an image side along an optical axis,

it is characterized in that the method comprises the steps of,

the first lens has negative 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, the object side surface of the second lens is concave, and the image side surface of the second lens is convex;

the third lens is a biconvex lens with positive focal power;

the fourth lens has negative focal power;

the fifth lens has positive optical power, and the fifth lens and the fourth lens are glued; and

the sixth lens element with positive refractive power has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, a convex object-side surface at a far-axis region, and a concave image-side surface at a far-axis region;

wherein TTL/F is not less than 4.5 and not more than 7, TTL is the optical length of the optical lens, and F is the whole set of focal length values of the optical lens.

2. The optical lens of claim 1, wherein plastic lenses are arranged in the first lens to the sixth lens, and the number of the plastic lenses is less than or equal to 2.

3. The optical lens of claim 1, wherein the first lens and the sixth lens are aspherical lenses.

4. The optical lens of claim 1, wherein one or both of the second lens and the sixth lens is or are plastic lenses, and wherein the plastic lenses are aspheric lenses.

5. The optical lens of claim 1, wherein the fourth lens is a biconcave lens and the fifth lens is a biconvex lens.

6. The optical lens of any one of claims 1 to 5, further comprising a stop located between the third lens and the fourth lens.

7. An optical lens according to any one of claims 1 to 5, wherein 2.5.ltoreq.F6/F.ltoreq.6.5,

wherein F6 is a focal length of the sixth lens, and F is a focal length value of the entire group of the optical lens.

8. An optical lens as claimed in any one of claims 1 to 5, characterized in that,

FOV≥85°，

wherein FOV is the field angle of the optical lens.

9. An optical lens according to any one of claims 1 to 5, wherein-7.5.ltoreq.F2/F.ltoreq.3.5,

10. An optical lens in which the number of lenses having optical power is six, which are respectively a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, the first lens to the sixth lens being arranged in order from an object side to an image side along an optical axis,

it is characterized in that the method comprises the steps of,

the third lens is a biconvex lens with positive focal power;

the fifth lens and the fourth lens are glued; and

the sixth lens element with positive refractive power has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, a convex object-side surface at a far-axis region, a concave image-side surface at a far-axis region,

wherein F6/F is 2.5 or less and 5.05302278, F6 is the focal length of the sixth lens, F is the whole set of focal length values of the optical lens,

wherein 6.1244973 is less than or equal to TTL/F is less than or equal to 7, TTL is the optical length of the optical lens, and F is the whole set of focal length values of the optical lens.

11. The optical lens of claim 10, wherein plastic lenses are arranged in the first lens to the sixth lens, and the number of the plastic lenses is less than or equal to 2.

12. The optical lens of claim 10, wherein the first lens and the sixth lens are aspherical lenses.

13. The optical lens of claim 10, wherein one or both of the second lens and the sixth lens is or are plastic lenses, and wherein the plastic lenses are aspheric lenses.

14. The optical lens of claim 10, wherein the fourth lens is a biconvex lens having positive optical power and the fifth lens is a biconcave lens having negative optical power.

15. The optical lens of claim 10, wherein the fourth lens is a biconcave lens having negative optical power and the fifth lens is a biconvex lens having positive optical power.

16. The optical lens of any one of claims 10 to 15, further comprising a stop located between the third lens and the fourth lens.

17. An optical lens as claimed in any one of claims 10 to 15, characterized in that,

FOV≥85°，

wherein FOV is the field angle of the optical lens.

18. An optical lens as claimed in any one of claims 10 to 15, characterized in that,

-7.5≤F2/F≤-3.5，

19. An imaging apparatus comprising the optical lens according to any one of claims 1 to 18 and an imaging element for converting an optical image formed by the optical lens into an electric signal.