CN113156611A - Optical lens and imaging apparatus - Google Patents

Abstract

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

Description

Optical lens and imaging apparatus

Divisional application statement

The application is a divisional application of a Chinese invention patent application with the invention name of 'optical lens and imaging device' and the application number of 201710116963.1, filed on 2017, 03, and 01.

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, a Charge Coupled Device (CCD) and a Complementary Metal Oxide Semiconductor (CMOS) as a solid-state imaging element have been well known.

With the development of science and technology, the requirements for resolving power of optical lenses are higher and higher. For such a lens that works in an outdoor environment, such as a monitoring lens or a vehicle-mounted lens, the resolution requirement 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 kept in hot and high-temperature days and cold rainy and snowy days.

In particular, the vehicular forward-view lens relates to active safety, and the influence of temperature on the imaging of the lens is generally stricter in the control of back focus offset. Because the temperature has a large influence on the performance parameters of the plastic lens and easily influences the imaging quality of the lens, the conventional vehicle-mounted front-view lens generally does not contain the plastic lens, but adopts the glass lens, so that the weight of the lens is increased, and the cost can be greatly improved if high resolution is achieved.

Meanwhile, the vehicle-mounted forward-looking lens is usually required to be far away to detect a front distant-direction object, the focal length of the corresponding lens is longer, but the field angle of the lens is limited, so that the field angle of the lens is small. Therefore, the conventional vehicle-mounted front-view lens has a small field angle, needs to be matched with a wide-angle lens with a large field angle range to expand the whole observation field, and is combined with software to complete picture splicing.

Accordingly, there is a need for improved optical lenses and imaging devices.

Disclosure of Invention

The present invention has been made to address the above-mentioned drawbacks and deficiencies of the prior art, and it is an object of the present invention 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 invention 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 the shape setting of each lens and the reasonable matching of the power setting, 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 invention is to provide an optical lens and an imaging apparatus which realize a large angle of view by shape setting of respective lenses, thereby enlarging the entire observation field of view.

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

According to an aspect of the present invention, there is provided an optical lens, wherein the number of lenses having a refractive power is six, and the lenses 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 are arranged in order from an object side to an image side along an optical axis, wherein an object side surface of the first lens is a convex surface, and an image side surface of the first lens is a concave surface; 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; the third lens element is characterized in that a paraxial object-side surface of the third lens element is convex, a paraxial image-side surface of the third lens element is concave, a high beam object-side surface of the third lens element is convex, and a high beam image-side surface of the third lens element is concave.

In the above optical lens, the sixth lens has a positive refractive power.

In the above optical lens, the first to sixth lenses include plastic lenses, 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 are plastic lenses, and the plastic lenses are aspheric lenses.

In the above optical lens, the fourth lens is a double convex lens having positive power, and the fifth lens is a double concave lens having negative power.

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

In the above optical lens, the first lens has a negative refractive power.

In the above optical lens, the second lens has a negative refractive power.

In the above optical lens, the fifth lens is cemented with the fourth lens.

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

In the optical lens, F2/F is more than or equal to-7.5 and less than or equal to-3.5, wherein F2 is the focal length of the second lens, and F is the whole group focal length value of the optical lens.

In the optical lens, 2.5 ≦ F6/F ≦ 6.5, where F6 is the focal length of the sixth lens and F is the entire group focal length value of the optical lens.

In the above optical lens, FOV is 85 degrees or more, wherein FOV is the angle of view of the optical lens.

In the optical lens, TTL/F is not less than 4.5 and not more than 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 invention, there is provided an optical lens, wherein the number of lenses having a refractive power is six, and the lenses 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 are arranged in order from an object side to an image side along an optical axis, wherein an object side surface of the first lens is a convex surface, and an image side surface of the first lens is a concave surface; 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 has positive optical power; the sixth lens element has a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region, and has a convex object-side surface at a distance from the paraxial region and a concave image-side surface at a distance from the paraxial region; wherein, F2/F is not less than 7.5 and not more than-3.5, wherein, F2 is the focal length of the second lens, and F is the whole focal length value of the optical lens.

In the above optical lens, the sixth lens has a positive refractive power.

In the above optical lens, the first to sixth lenses include plastic lenses, 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 are plastic lenses, and the plastic lenses are aspheric lenses.

In the above optical lens, the fourth lens is a double convex lens having positive power, and the fifth lens is a double concave lens having negative power.

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

In the above optical lens, the first lens has a negative refractive power.

In the above optical lens, the second lens has a negative refractive power.

In the above optical lens, the fifth lens is cemented with the fourth lens.

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

In the optical lens, 2.5 ≦ F6/F ≦ 6.5, where F6 is the focal length of the sixth lens.

In the above optical lens, FOV is 85 degrees or more, wherein FOV is the angle of view of the optical lens.

In the optical lens, TTL/F is not less than 4.5 and not more than 7, wherein TTL is the optical length of the optical lens.

In the above optical lens, the third lens is a biconvex lens.

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

The optical lens and the imaging device provided by the invention can improve the optical performance of the lens by adopting the plastic lens, and simultaneously, the optical lens has better temperature performance and reduces the cost and the weight by reasonably matching the shape of the lens, the focal power of the plastic lens and the focal powers of other lenses.

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

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

Drawings

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

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

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

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

fig. 5A is a schematic view of an imaging effect of the optical lens according to the first embodiment of the present invention at normal temperature;

FIG. 5D is a schematic diagram illustrating an imaging effect of the optical lens assembly according to the first embodiment of the present invention at a high temperature;

fig. 5B and 5C are schematic diagrams illustrating an imaging effect of the 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 invention.

Detailed Description

The following description is presented 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 basic 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.

The terms and words used in the following specification and claims are not limited to the literal meanings, but are used only by the inventors to enable a clear and consistent understanding of the invention. Accordingly, it will be apparent to those skilled in the art that the following descriptions of the various embodiments of the present invention are provided for illustration only and not for the purpose of limiting the invention 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 forms are intended to include the plural forms 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, numbers, steps, operations, components, elements, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, elements, or groups thereof.

Terms used herein, including technical and scientific terms, have the same meaning as terms commonly understood by one of ordinary skill in the art, unless otherwise defined. It will be understood that terms defined in commonly used dictionaries have meanings that are consistent with their meanings in the prior art.

The invention is described in further detail below with reference to the following figures and detailed description:

[ arrangement of optical lens ]

According to the optical lens of the embodiment of the present invention, the 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; a third lens which 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.

The second lens is preferably an aspheric lens, and more preferably, the second lens may be an aspheric lens with approximately concentric circles.

Wherein the fourth lens and the fifth lens have opposite optical powers to each other. For example, when the fourth lens has a positive power, the fifth lens has a negative power, and when the fourth lens has a negative power, the fifth lens has a positive power. And, the fourth lens and the fifth lens cemented to each other have mutually opposite concavo-convex shapes. 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 has a convex object-side surface and a concave image-side surface. Preferably, the object side surface of the far optical axis of the sixth lens is also convex, and the image side surface of the far optical axis is also concave.

Through the shape setting and the focal power setting of the lenses, one or more plastic lenses can be adopted in the first lens, the second lens, the third lens and the fourth lens, so that good imaging quality is obtained by adopting the plastic lenses, and meanwhile, good temperature performance is guaranteed.

Preferably, in an optical lens according to an embodiment of the present invention, 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 are plastic lenses. According to an embodiment of the present invention, the second lens and the sixth lens are both plastic lenses, and the plastic lenses are aspheric. ,

preferably, the first lens to the sixth lens 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 lens to the sixth lens 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 focal length value of the optical lens.

Therefore, the optical lens according to the embodiment of the invention can adopt the plastic lens among the plurality of lenses, can realize a larger degree of plasticization particularly when being applied to the vehicle-mounted front-view lens, and solves the problem that the vehicle-mounted front-view lens relates to active safety, and cannot use the plastic lens, so that the imaging quality cannot be improved while the cost is reduced.

In the optical lens according to the embodiment of the invention, although the plastic lens is used, through the shape setting of each lens, the optical power setting of the plastic lens and the reasonable matching of the optical power of other lenses, the problem that the resolution is greatly influenced by temperature when the plastic lens is used is solved, so that the optical lens has good temperature performance, and the cost and the 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 the FOV is the field angle of the optical lens.

In this way, in the optical lens according to the embodiment of the present invention, a large angle of view is achieved, thereby enlarging the overall observation field of view. Therefore, when applied to the in-vehicle front view lens, since it is not necessary to enlarge the entire observation field of view in cooperation with a wide-angle lens having a large field angle range, it is possible to further save the lens cost of the driving assist system using the in-vehicle front view lens.

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 an optical length of the optical lens, that is, a distance from an outermost point of the object side of the first lens to the imaging focal plane.

Therefore, according to the embodiments of the present invention, a miniaturized optical lens can be obtained.

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

In the optical lens system according to the embodiment of the invention, the first lens element has a meniscus shape convex toward the object side, and the object side surface of the first lens element is convex and the image side surface of the first lens element is concave. The first lens is curved toward the object side, so that the incident angle of the incident light on the attack surface is small, and the optical system of the embodiment of the invention is favorable for collecting more light to enter. In addition, when applied to an on-vehicle front-view lens, the convex surface is advantageous for outdoor use in adaptation to the on-vehicle front-view lens. For example, the convexity may assist in the sliding of water droplets when in an environment such as rainy weather.

In the optical lens system according to the embodiment of the invention, the second lens element has a meniscus shape convex to the image side, the object side of the second lens element is concave, and the image side of the second lens element is convex. Because the first lens of the optical lens is a divergent lens, the meniscus lens configuration of the second lens is utilized to make the trend of the off-axis light relatively smooth, so that the light can be smoothly transited to the rear. The second lens is an aspherical lens, and its aspherical surface has a certain correction for axial and external point aberrations. In addition, more preferably, the second lens can be an aspheric lens close to a concentric circle, so that the design and processing of the lens are facilitated, and the aspheric cost can be reduced.

In the optical lens system according to the embodiment of the invention, the third lens element is a biconvex lens element, and the object-side surface of the third lens element is a convex surface and the image-side surface of the third lens element is a convex surface. The third lens is a converging lens, and the light rays are compressed to smoothly pass through the third lens, so that the light flux of the system is increased. In addition, the third lens is preferably made of a high-refractive-index low-Abbe number material to compensate for on-axis aberrations generated by the first and second lenses.

In the optical lens according to the embodiment of the present invention, the fourth lens and the fifth lens cemented to each other can correct chromatic aberration by themselves, while the fourth lens and the fifth lens cooperate with each other, and can compensate on-axis point monochromatic aberration while compensating for residual color.

In the optical lens system according to the embodiment of the invention, the sixth lens element is a meniscus lens element convex toward the object side, and is an aspheric lens element having a convex object-side surface and a concave image-side surface. The sixth lens is a positive lens, so that light rays are converged, and the aspheric surface is used for better compensating the off-axis point aberration. Preferably, the object-side surface of the far-optical axis of the sixth lens is also convex, and the image-side surface of the far-optical axis is also concave

In the above optical lens, a stop is further included. Preferably, the diaphragm is located between the third lens and the fourth lens, so that light rays entering the optical system are effectively converged, and the aperture of a lens of the optical system is reduced. Of course, the skilled person will understand that the diaphragm may also be located between any other discrete lenses.

Further, in the case where the optical lens according to the embodiment of the present invention includes the diaphragm, it is preferable to dispose the fourth lens and the fifth lens cemented to each other at positions close to the diaphragm in consideration of the balance of system aberrations and the rationality of the structure.

And the third lens can compress the light rays to enable the light rays to smoothly enter the diaphragm, so that the aperture of the diaphragm can be increased, and the light flux of the system can be increased. Moreover, the sixth lens can further reduce the aperture value FNO and increase the aperture of the system.

In the optical lens according to the embodiment of the present invention, when two plastic lenses are used, the two plastic lenses are main factors that affect the back focus variation at different temperatures, thereby affecting the temperature performance. Therefore, the emphasis assignment limits the optical powers of the two plastic lenses, e.g., the second lens and the sixth lens, to be matched with the optical powers of the other glass lenses, so that the temperature performance of the entire optical system is improved.

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

[ numerical example of optical lens ]

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

Some of the lenses used in the embodiments have an aspherical lens surface, and the aspherical surface shape is represented by the following expression (5):

wherein, z (h) is a distance rise from the vertex of the aspherical surface when the aspherical surface is at a position of height h in the optical axis direction.

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

In addition, Nd denotes a refractive index, and Vd denotes an abbe number.

First embodiment

As shown in fig. 1, the optical lens according to the first embodiment of the present invention includes, in order from an object side to an image side: a meniscus-shaped first lens L1 with negative power having a first surface S1 convex to the object side and a second surface S2 concave to 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 power having a first surface S3 concave to the object side and a second surface S4 convex to 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 third lens L3 having positive optical power and having a first surface S5 convex to the object side and a second surface S6 convex to the image side; a diaphragm STO; a fourth lens L4 and a fifth lens L5 cemented with each other, in which the fourth lens L4 is a biconcave shape having a negative power, having a first surface S8 concave to the object side and a second surface S9 concave to the image side, the fifth lens L5 is a biconvex shape having a positive power, having 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 having positive power, having a convex object-side first surface S11 and a concave image-side second surface S12; a planar lens L7 having a first surface S13 facing the object side and a second surface S14 facing 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 protective glass, for protecting the image plane; l9 has an image plane S17, typically a chip.

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

[ TABLE 1 ]

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

[ TABLE 2 ]

Surface of

k

A

B

C

D

E

3

0.1800

6.0543E-03

1.2841E-05

2.2610E-05

-2.8216E-06

2.3519E-07

4

0.5230

3.3743E-03

2.1250E-04

-4.6594E-06

4.5323E-06

-1.5911E-07

11

1.8367

-3.0810E-04

2.5109E-04

-8.0385E-05

1.7169E-05

-1.3286E-06

12

50.0000

3.1282E-03

1.7108E-04

1.7856E-04

4.7057E-05

-2.9816E-06

In the optical lens according to the first embodiment of the present invention, the focal length F2 of the second lens, the focal length F6 of the sixth lens, the entire group focal length value F of the optical lens, and the optical length TTL of the optical lens and the relationship therebetween are as 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 invention satisfies the aforementioned conditional expressions (1), (2), and (4), thereby achieving good temperature performance and miniaturization of the optical lens.

Second embodiment

As shown in fig. 2, the optical lens according to the second embodiment of the present invention, in order from an object side to an image side, comprises: a meniscus-shaped first lens L1 with negative power having a first surface S1 convex to the object side and a second surface S2 concave to 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 power having a first surface S3 concave to the object side and a second surface S4 convex to 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 third lens L3 having positive optical power and having a first surface S5 convex to the object side and a second surface S6 convex to the image side; a diaphragm STO; a fourth lens L4 and a fifth lens L5 cemented with each other, in which the fourth lens L4 is a biconcave shape having a negative power, having a first surface S8 concave to the object side and a second surface S9 concave to the image side, the fifth lens L5 is a biconvex shape having a positive power, having 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 having positive power, having a convex object-side first surface S11 and a concave image-side second surface S12; a planar lens L7 having a first surface S13 facing the object side and a second surface S14 facing 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 protective glass, for protecting the image plane; l9 has an image plane S17, typically a chip.

The lens data for the above lenses are shown in table 4 below:

[ TABLE 4 ]

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

[ TABLE 5 ]

Surface of

k

A

B

C

D

E

3

-0.1821

6.9368E-03

1.6110E-06

3.1060E-05

-5.2184E-06

4.8545E-07

4

0.1714

3.8661E-03

2.6660E-04

-7.4007E-05

6.8174E-06

-2.6206E-07

11

3.1477

-7.2840E-04

1.1204E-03

-5.6072E-04

3.1472E-04

-3.1156E-05

12

-36.3727

7.3956E-03

2.4493E-03

-1.3296E-03

5.0840E-04

-7.5995E-05

In the optical lens according to the second embodiment of the present invention, the focal length F2 of the second lens, the focal length F6 of the sixth lens, the entire group focal length value F of the optical lens, and the optical length TTL of the optical lens and the relationship therebetween are as 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 invention satisfies the aforementioned conditional expressions (1), (2), and (4), thereby achieving good temperature performance and miniaturization of the optical lens.

Third embodiment

As shown in fig. 3, the optical lens according to the third embodiment of the present invention, in order from an object side to an image side, comprises: a meniscus-shaped first lens L1 with negative power having a first surface S1 convex to the object side and a second surface S2 concave to 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 power having a first surface S3 concave to the object side and a second surface S4 convex to 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 third lens L3 having positive optical power and having a first surface S5 convex to the object side and a second surface S6 convex to the image side; a diaphragm STO; a fourth lens L4 and a fifth lens L5 cemented with each other, in which the fourth lens L4 is a biconvex shape having positive optical power, having a first surface S8 convex to the object side and a second surface S9 convex to the image side, the fifth lens L5 is a biconcave shape having negative optical power, having a first surface S9 concave to the object side and a second surface S10 concave to the image side; a meniscus-shaped sixth lens L6 having positive power, having a convex object-side first surface S11 and a concave image-side second surface S12; a planar lens L7 having a first surface S13 facing the object side and a second surface S14 facing 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 protective glass, for protecting the image plane; l9 has an image plane S17, typically a chip.

The lens data for the above lenses are shown in table 7 below:

[ TABLE 7 ]

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

[ TABLE 8 ]

Surface of

k

A

B

C

D

E

3

0.3931

3.7310E-03

5.7307E-06

7.3070E-06

-6.5636E-07

3.9665E-08

4

7.7359

2.0794E-03

9.4834E-05

-1.5058E-05

1.2450E-06

-3.6268E-08

11

2.8815

-1.8987E-04

1.1206E-04

-2.4338E-05

4.0183E-06

-2.2517E-07

12

7339.6910

1.9278E-03

2.4243E-05

-5.7708E-05

8.0831E-06

-4.4634E-09

In the optical lens according to the third embodiment of the present invention, the focal length F2 of the second lens, the focal length F6 of the sixth lens, the entire group focal length value F of the optical lens, and the optical length TTL of the optical lens and the relationship therebetween are as 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 invention satisfies the aforementioned 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 the fourth embodiment of the present invention, in order from an object side to an image side, comprises: a meniscus-shaped first lens L1 with negative power having a first surface S1 convex to the object side and a second surface S2 concave to 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 power having a first surface S3 concave to the object side and a second surface S4 convex to 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 third lens L3 having positive optical power and having a first surface S5 convex to the object side and a second surface S6 convex to the image side; a diaphragm STO; a fourth lens L4 and a fifth lens L5 cemented with each other, in which the fourth lens L4 is a biconcave shape having a negative power, having a first surface S8 concave to the object side and a second surface S9 concave to the image side, the fifth lens L5 is a biconvex shape having a positive power, having 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 having positive power, having a convex object-side first surface S11 and a concave image-side second surface S12; a planar lens L7 having a first surface S13 facing the object side and a second surface S14 facing 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 protective glass, for protecting the image plane; l9 has an image plane S17, typically a chip.

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

[ TABLE 10 ]

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

[ TABLE 11 ]

Surface of

k

A

B

C

D

E

3

-0.5935

1.1666E-02

2.6220E-06

1.0447E-04

-2.0066E-05

2.5929E-06

4

0.1717

8.7439E-03

6.3407E-04

-2.1529E-05

6.0599E-05

-4.8028E-06

11

2.9703

-5.9369E-04

7.3712E-04

-3.4795E-04

1.2284E-04

-1.4720E-05

12

-55.2699

6.0278E-03

1.7419E-03

-8.3810E-04

2.7528E-05

-2.9178E-06

In the optical lens according to the fourth embodiment of the present invention, the focal length F2 of the second lens, the focal length F6 of the sixth lens, the entire group focal length value F of the optical lens, and the optical length TTL of the optical lens, and the relationship therebetween are as 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 invention satisfies the aforementioned conditional expressions (1), (2), and (4), thereby achieving good temperature performance and miniaturization of the optical lens.

Effect of imaging

The dot charts of fig. 5A to 5D show the condensing states of the light rays of different wavelengths on the image plane. Generally, the larger the field angle, the larger the peripheral field position aberration, the weaker the light condensing ability, and the lower the imaging quality than the center.

Fig. 5A is a dot sequence diagram showing the lens peripheral field positions in the optical lens according to the first embodiment of the present invention at normal temperature. As shown in fig. 5A, the light is concentrated in the dispersed spot, and the light is condensed well in each color, so that the image quality of the image is excellent and the resolution is good.

Fig. 5B is a diagram corresponding to a dot arrangement on the same peripheral image plane, in which the best image plane shift amount due to the expansion of the plastic lens at high temperature is too large if 3 or more plastic aspherical lenses are used. As shown in fig. 5B, the scattered dots are dispersed, the condensing performance is poor under each color light, the image quality is poor, and the resolution is low.

Fig. 5C corresponds to an effect that can be achieved by the optical lens of the prior art in the position range with a small angle of view at a high temperature. As shown in fig. 5C, the diffuse speckles are more concentrated, and the imaging quality of the image is still acceptable.

Fig. 5D shows that the optical lens according to the first embodiment of the present invention can achieve the following effects at high temperature even when 2 plastic lenses are used and the peripheral field position with the enlarged field angle is still achieved. As shown in fig. 5D, the diffuse spots are more concentrated and the image quality is better.

In summary, according to the optical lens of the embodiment of the invention, the plastic lens is adopted to improve the optical performance of the lens, and meanwhile, the optical power of the plastic lens is reasonably matched with the optical power of other lenses through the shape setting of the lens, so that the optical lens has better temperature performance, and the cost and the weight are reduced.

In addition, the optical lens according to the embodiment of the invention realizes a large field angle and enlarges the whole observation field.

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

[ configuration of image Forming apparatus ]

According to another aspect of embodiments of the present invention, 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 electric 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; a third lens which 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 invention. As shown in fig. 6, an imaging apparatus 100 according to an embodiment of the present invention includes an optical lens 101 and an imaging element 102. The optical lens 101 is used for capturing an optical image of a subject, and the imaging element 102 is used for converting the optical image captured by the optical lens 101 into an electrical signal.

In the above optical lens system, the sixth lens element has a convex paraxial object-side surface and a concave paraxial image-side surface, and the sixth lens element has a convex paraxial object-side surface and a concave high-beam image-side surface.

In the optical lens, the first lens to the sixth lens of the optical lens are plastic lenses, 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 are plastic lenses, and the plastic lenses are aspheric.

In the above-described imaging apparatus, the fourth lens is a double convex lens having positive power, and the fifth lens is a double concave lens having negative power.

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

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

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 whole set of focal length values of the optical lens.

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 the focal length of the sixth lens, and F is the whole focal length 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)

where the 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 imaging apparatus, the third lens is made of a high refractive index low abbe number material.

Here, it can 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 invention are the same as those described above with respect to the optical lens according to the embodiment of the present invention, and the aforementioned numerical examples of the optical lens according to the first to fourth embodiments of the present invention may be adopted, and therefore, no trace is made again in order to avoid redundancy.

According to the optical lens and the imaging device provided by the embodiment of the invention, the optical performance of the lens can be improved by adopting the plastic lens, and meanwhile, the optical lens has better temperature performance and the cost and the weight are reduced by reasonably matching the shape of the lens, the focal power of the plastic lens and the focal power of other lenses.

Moreover, the optical lens and the imaging device according to the embodiment of the invention realize a large field angle and enlarge the whole observation field.

Further, the optical lens and the imaging apparatus according to the embodiments of the present invention realize miniaturization of the lens.

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

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 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 (10)

1. An optical lens in which the number of lenses having power is six, and is 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 preparation method is characterized in that,

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 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;

the third lens element is characterized in that a paraxial object-side surface of the third lens element is convex, a paraxial image-side surface of the third lens element is concave, a high beam object-side surface of the third lens element is convex, and a high beam image-side surface of the third lens element is concave.

2. An optical lens according to claim 1, characterized in that the sixth lens has a positive optical power.

3. An optical lens barrel according to claim 1, wherein there are plastic lenses among the first to sixth lenses, and the number of plastic lenses is less than or equal to 2.

4. An optical lens according to claim 1, characterized in that the first lens and the sixth lens are aspherical lenses.

5. An optical lens according to claim 1, wherein one or both of the second lens and the sixth lens are plastic lenses, and the plastic lenses are aspheric lenses.

6. An optical lens according to claim 1, characterized in that the fourth lens is a double convex lens having a positive optical power, and the fifth lens is a double concave lens having a negative optical power.

7. An optical lens according to claim 1, characterized in that the fourth lens is a biconcave lens having a negative optical power and the fifth lens is a biconvex lens having a positive optical power.

8. An optical lens according to any one of claims 1 to 7,

2.5≤F6/F≤6.5，

wherein F6 is the focal length of the sixth lens, and F is the entire set of focal length values of the optical lens.

9. An optical lens in which the number of lenses having power is six, and is 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 preparation method is characterized in that,

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 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 has positive optical power;

the sixth lens element has a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region, and has a convex object-side surface at a distance from the paraxial region and a concave image-side surface at a distance from the paraxial region;

wherein F2/F is not less than-7.5 and not more than-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.

10. An imaging apparatus comprising the optical lens of any one of claims 1 to 9 and an imaging element for converting an optical image formed by the optical lens into an electrical signal.

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