CN114397750A

CN114397750A - 6mm day and night dual-purpose high-definition glass-plastic mixed prime lens

Info

Publication number: CN114397750A
Application number: CN202111671108.XA
Authority: CN
Inventors: 薛雷涛; 殷海明
Original assignee: Dongguan Changyi Photoelectric Co ltd
Current assignee: Dongguan Changyi Photoelectric Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-04-26

Abstract

The invention relates to the field of optical imaging, and discloses a 6mm day and night dual-purpose high-clarity glass-plastic mixed prime lens which comprises a lens, wherein the surface of one side of the lens, which is adjacent to an object plane, is defined as an object side surface, the surface of one side of the lens, which is adjacent to an image plane, is defined as an image side surface, and the lens sequentially comprises the following components from the object side to the image side along the optical axis of the lens: the 6mm day and night high-clear glass-plastic mixed fixed-focus lens adopts a mixed combination of 1 piece of spherical glass and 3 pieces of aspheric plastic, so that the high and low temperature drift of the system can be well corrected, the first lens to the fourth lens are respectively negative focal power, positive focal power and negative focal power, the distribution combination of different materials and focal power lenses is adopted, the aberration of the system is well corrected, the optical performance is good, the shape and the thickness of each lens are normal, the structure is simple, the insensitivity of each lens on the aspect of manufacturability is ensured, and the surface type of each lens is simple and easy to manufacture.

Description

6mm day and night dual-purpose high-definition glass-plastic mixed prime lens

Technical Field

The invention relates to the field of optical imaging, in particular to a 6mm day and night high-definition glass-plastic mixed prime lens.

Background

In recent years, a plurality of series of products have been introduced to the monitoring lens for different purposes of use or environments, wherein a 6mm day and night dual-purpose high-definition glass-plastic hybrid fixed-focus lens also becomes one of mainstream products of fixed-focus lenses, but the requirements of people on the lenses are higher and higher, and the overall trend is towards high performance and low cost. The existing lens in the market also has the problems of poor image quality and high cost, for example, poor image quality in severe weather and difficult confocal imaging in daytime and at night, and how to improve the performance of the lens and reduce the production cost is a problem to be solved urgently.

Disclosure of Invention

The present invention is directed to overcoming the above-mentioned shortcomings, and providing a technical solution to solve the above-mentioned problems.

The utility model provides a dual-purpose high clear glass of 6mm day night is moulded and is mixed tight shot which characterized in that, includes lens, and the surface that defines lens near object plane one side is the object side, and the surface that lens near image plane one side is the image side, lens include by the thing side to the image side along the camera lens optical axis in proper order: the first lens (1) is an aspheric plastic lens with negative focal power, and the object side surface of the first lens is a concave surface; the second lens (2) is a spherical glass lens with positive focal power, and the object side surface of the second lens is a convex surface while the image side surface of the second lens is a convex surface; the third lens (3) is an aspheric plastic lens with positive focal power, and the object side surface of the third lens is a convex surface while the image side surface of the third lens is a convex surface; the fourth lens (4) is an aspheric plastic lens with negative focal power, and the object side surface of the fourth lens is a concave surface while the image side surface of the fourth lens is a convex surface; be provided with aperture diaphragm (8) between first lens (1) and second lens (2), the rear of fourth lens (4) still is provided with: the optical filter (5), the optical filter (5) is made of H-K9L; a cover glass (6) integrated on a sensor (image sensor); an image pickup element (7); the ratio of the focal length of each lens to the total focal length of the system of the lens meets the following conditions:

0.76≤|f1/f|≤1.70；

0.97≤|f2/f|≤3.07；

0.56≤|f3/f|≤0.90；

0.70≤|f4/f|≤1.74；

in the relation, "f" is a focal length of the lens optical system, "f 1" is a focal length of the first lens (1), "f 2" is a focal length of the second lens (2), "f 3" is a focal length of the third lens (3), and "f 4" is a focal length of the fourth lens (4).

As an improvement of the above technical solution, the focal length, refractive index and radius of curvature of the first lens (1) to the fourth lens (4) satisfy the following conditions:

f1

-10.77~-4.67

ND1

1.52~1.56

R11

-9.55~-4.54

R12

+6.43~+15.95

f2

+5.74~+19.13

ND2

1.53~1.77

R21

+6.76~+22.98

R22

-2011.09~-6.90

f3

+3.28~+5.70

ND3

1.52~1.56

R31

+4.77~+11.28

R32

-4.59~-2.36

f4

-10.53~-4.06

ND4

1.60~1.66

R41

-2.53~-1.53

R42

-6.73~-3.86

in the above table, "f 1" is the focal length of the first lens (1), "ND 1" is the refractive index of the first lens (1), "R11, R12" is the front-rear surface curvature radius of the first lens (1), "f 2" is the focal length of the second lens (2), "ND 2" is the refractive index of the second lens (2), "R21, R22" is the front-rear surface curvature radius of the second lens (2), "f 3" is the focal length of the third lens (3), "ND 3" is the refractive index of the third lens (3), "R31, R32" is the front-rear surface curvature radius of the third lens (3), "f 4" is the focal length of the fourth lens (4), "ND 4" is the refractive index of the fourth lens (4), "R41, R42" is the front-rear surface curvature radius of the fourth lens (4), "sign" indicates that the direction is negative, and so on.

As one improvement of the technical scheme, IC/TTL is more than or equal to 0.29; OBFL/TTL is more than or equal to 0.31 and less than or equal to 0.44; in the relation, the focal length of the lens optical system is f; the total length of the lens optical system is TTL; the optical rear intercept of the lens system is OBFL, namely the distance from one point, closest to the image surface, of the image side surface of the fourth lens (4) to the image surface; the 1/2.7 inch chip matched with the lens system has the full image height of IC.

As one improvement of the technical scheme, the aperture of the optical lens is F #, the F # is more than or equal to 1.90 and less than or equal to 2.40, and the total length of the lens optical system is TTL, and the TTL is less than or equal to 22.50 mm.

As one improvement of the technical scheme, the aspheric surfaces of the first lens (1), the third lens (3) and the fourth lens (4) can be defined by the following equation of even aspheric surfaces:

in the formula, k is a conic coefficient of a conic surface, r is a lens height, c is a lens curvature, and A-G are coefficients of 4 th, 6 th, 8 th, 10 th, 12 th, 14 th and 16 th order terms of an aspheric polynomial.

As one improvement of the technical scheme, the maximum distance between the third lens (3) and the fourth lens (4) on the central axis is not more than 0.38 mm.

Compared with the prior art, the invention has the beneficial effects that: the 6mm day and night high-clarity glass-plastic mixed prime lens is formed by mixing and combining 1 piece of spherical glass and 3 pieces of non-spherical plastic, therefore, the high and low temperature drift of the system can be well corrected, the first lens to the fourth lens are respectively negative focal power, positive focal power and negative focal power, the distribution combination of different materials and focal power lenses is realized, the aberration of the system is well corrected, the optical performance is good, the shape and the thickness ratio of each lens are normal, the structure is simple, the insensitivity of each lens is ensured in the aspect of manufacturability, the lens surface type is simple and easy to manufacture, the processing cost is relatively low in the market, the cost performance is higher, the characteristics of good performance and low cost can be realized, through reasonable lens material selection, focal power distribution and optical design optimization, the invention can be matched with a chip of 5MP and 1/2.7 inch, and realizes 24-hour all-weather high-definition monitoring.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of an optical structure according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an optical path structure according to an embodiment of the present invention;

FIG. 3 is a field curvature diagram of 0.546um visible light according to an embodiment of the present invention;

FIG. 4 is a diagram of visible 0.546um distortion according to an embodiment of the present invention;

FIG. 5 is a Lateral Color diagram according to an embodiment of the present invention.

In fig. 1: 1. a first lens; 2. a second lens; 3. a third lens; 4. a fourth lens; 5. an optical filter; 6. protecting glass; 7. an image pickup element; 8. and (4) an aperture diaphragm.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-5, in an embodiment of the present invention, a 6mm day and night dual-purpose high-definition glass-plastic hybrid prime lens includes a lens, a surface of the lens adjacent to an object plane is defined as an object side surface, and a surface of the lens adjacent to an image plane is defined as an image side surface, and as shown in fig. 1, the lens sequentially includes, from an object side to an image side along an optical axis of the lens: a first aspherical plastic lens (1) having a negative refractive power, the object-side surface of which is concave and the image-side surface of which is concave; a second spherical glass lens (2) with positive focal power, wherein the object side surface is a convex surface, and the image side surface is a convex surface; a third aspheric plastic lens (3) with positive focal power, wherein the object side surface is a convex surface, and the image side surface is a convex surface; a fourth aspherical plastic lens (4) having a negative refractive power, the object-side surface of which is concave and the image-side surface of which is convex; an aperture diaphragm (8) is arranged between the first lens (1) and the second lens (2). The invention only uses four lenses, has less data and compact structure, and ensures the small volume and light weight of the lens.

In order to make the optical system exhibit better performance, we need to select the lens material reasonably, distribute the focal length of each lens reasonably and optimize the optical system reasonably in the design process to correct the aberration of the system, and finally optimize the performance of the optical system. Referring to fig. 1, in the embodiment of the present invention, the focal length of the first lens (1) is f1, the focal length of the second lens (2) is f2, the focal length of the third lens (3) is f3, the focal length of the fourth lens (4) is f4, the focal lengths of the first lens (1) and the second lens (2) are f12, the focal length of the entire lens is f, and the ratio of each lens to the total focal length of the system satisfies the following conditions:

0.76≤|f1/f|≤1.70；

0.97≤|f2/f|≤3.07；

0.56≤|f3/f|≤0.90；

0.70≤|f4/f|≤1.74；

in an optical system, the focal length distribution of each lens is important, which determines the overall performance of the optical system, and the ratio of the focal length of each lens to the focal length f of the optical system is controlled in such a way that the day and night confocal performance and the high and low temperature performance of the system can be optimally represented.

Angle of field of view for embodiments of the invention>66 degrees, so that the first lens adopts a lens with a meniscus negative focal power with the convex surface facing the object space, the function of the lens is to quickly converge light rays, the abbe numbers of the first lens (1), the second lens (2) and the third lens (3) are more than 49, the abbe number of the fourth lens (4) is less than 24, the matching can reduce the chromatic aberration of the system, and the focal length, the material and the R value of each lens respectively meet the following conditions in consideration of the problems of aberration, balance temperature drift, day and night confocal of the optical system:

f1

-10.77~-4.67

ND1

1.52~1.56

R11

-9.55~-4.54

R12

+6.43~+15.95

f2

+5.74~+19.13

ND2

1.53~1.77

R21

+6.76~+22.98

R22

-2011.09~-6.90

f3

+3.28~+5.70

ND3

1.52~1.56

R31

+4.77~+11.28

R32

-4.59~-2.36

f4

-10.53~-4.06

ND4

1.60~1.66

R41

-2.53~-1.53

R42

-6.73~-3.86

The focal length of the integral optical system is f, the total optical length of the lens system is TTL, the optical back intercept of the lens system is OBFL, namely the distance from the point, closest to the image surface, of the image side surface of the fourth lens (4) to the image surface, the total image height of a 1/2.7' chip matched with the lens system is IC, and the following relations are satisfied:

IC/TTL≥0.29；

0.31≤OBFL/TTL≤0.44；

the aperture of the embodiment of the invention is F #, and the F # -is more than or equal to 1.90 and less than or equal to 2.40, the optical total length of the lens system is TTL, and the TTL is less than or equal to 22.50mm, the total length of the system is small, and the small volume is ensured.

According to the embodiment of the invention, the third lens (3) and the fourth lens (4) are relatively close, the maximum interval on the central axes is less than or equal to 0.38mm, the intervals on the central axes of the lenses are reasonably distributed, so that the sensitivity of the optical lens is favorably reduced, the optical resolution capacity is improved, and the third lens (3) and the fourth lens (4) are relatively close, so that the performance of the lens is favorably improved.

Referring to fig. 1 and fig. 2, which are respectively an optical structure schematic diagram and an optical path structure schematic diagram of a first embodiment of the present invention, the second lens (2) is a glass spherical surface, the first lens (1), the third lens (3) and the fourth lens (4) are plastic aspheric surfaces, a total focal length of the system is 6.0mm, an aperture value is 2.0, and a lens distortion is <15%, so that a difference between a shot image and a real object is small, and fig. 5 is a linear color of the system, so that chromatic aberration of the system is well corrected, and imaging quality of the system is ensured.

In the following table, the Number of optical surfaces (Surface Number) in order from the object side to the image side, the radius of curvature R (unit: mm) of each lens, the center thickness d (unit: mm) of each lens, the refractive index (ND) and abbe constant (VD) of each lens, and the aspherical Surface K value (conc) of each lens are listed.

Watch 1

Number of noodles	Radius of curvature R	Center thickness d	Refractive index ND	Abbe constant VD	K
						1	-6.68	1.00	1.53	55.7	-12.40
2	9.68	2.92			8.51
						3 (diaphragm)	Infinity	1.73
4	10.24	1.63	1.69	49.2
						5	-25.20	2.92
6	5.33	2.61	1.53	55.7	0.03
						7	-3.14	0.25			-5.80
8	-2.01	1.33	1.63	23.9	-3.03
						9	-5.53	0.12			-21.77
10	Infinity	0.70	1.51	64.2
						11	Infinity	6.65

In Table one, the face numbers are numbered according to the order of the surfaces of the respective lenses, wherein "1" represents the front surface of the first lens (1), "2" represents the rear surface of the first lens (1), and so on; the radius of curvature represents the degree of curvature of the lens surface, positive values represent the surface curving to the image plane side, and negative values represent the surface curving to the object plane side, wherein "Infinity" represents the surface being planar; the thickness represents the central axial distance from the current surface to the next surface, the refractive index represents the deflection capability of the current lens material to light rays, and the Abbe number represents the dispersion characteristic of the current lens material to the light rays; the K value represents the magnitude of the best fitting conic coefficient for the aspheric surface.

The aspheric surfaces of the first lens element (1), the third lens element (3) and the fourth lens element (4) according to the first embodiment of the present invention can be defined by the following equation of even aspheric surfaces:

in the formula, k is a conic coefficient of a quadric surface, r is the lens height, c is the lens curvature, and A-G are coefficients of 4 th order, 6 th order, 8 th order, 10 th order, 12 th order, 14 th order and 16 th order of the aspheric polynomial.

The following two lists have the coefficients of the aspheric surfaces of the optical surfaces:

watch two

Number of noodles

A

B

C

D

E

1

2.83E-04

-1.62E-04

1.56E-05

-5.50E-07

0.00E+00

2

4.16E-03

-6.72E-04

4.05E-05

-3.93E-08

-2.34E-07

6

2.33E-04

-5.60E-05

3.92E-06

-5.66E-07

-1.53E-08

7

-8.13E-03

2.12E-03

-2.16E-04

-3.39E-07

1.01E-06

8

-4.03E-04

1.53E-03

-2.50E-04

1.06E-05

4.55E-07

9

1.17E-03

2.00E-03

-4.10E-04

4.16E-05

-1.67E-06

In summary, the following steps: the 6mm day and night dual-purpose high-clarity glass-plastic mixed prime lens adopts the mixed combination of 1 piece of spherical glass and 3 pieces of non-spherical plastic, the aberration of a system is well corrected, the optical performance is good, under the condition of achieving the same quality in the industry, each lens is not sensitive, the lens surface type is simple and easy to manufacture, the processing cost is relatively low on the market, the lens has the characteristics of higher cost performance, good performance and low cost, the invention comprehensively considers the problems of the aberration, the balance temperature drift, day and night confocal and the like of an optical system, can be matched with a 5MP and 1/2.7 inch chip through reasonable lens material selection, optical power distribution and optical design optimization, realizes 24-hour all-weather high-definition monitoring, satisfies day and night imaging, ensures that the lens can be shot clearly at night, and has clear real shooting pictures at high temperature of 80 ℃ and low temperature of 40 ℃ in severe environment, the consistency of image quality under different conditions is realized, and the resolution can reach five million pixels.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. The utility model provides a dual-purpose high clear glass of 6mm day night is moulded and is mixed tight shot which characterized in that, includes lens, and the surface that defines lens near object plane one side is the object side, and the surface that lens near image plane one side is the image side, lens include by the thing side to the image side along the camera lens optical axis in proper order:

the first lens (1) is an aspheric plastic lens with negative focal power, and the object side surface of the first lens is a concave surface;

the second lens (2) is a spherical glass lens with positive focal power, and the object side surface of the second lens is a convex surface while the image side surface of the second lens is a convex surface;

the third lens (3) is an aspheric plastic lens with positive focal power, and the object side surface of the third lens is a convex surface while the image side surface of the third lens is a convex surface;

the fourth lens (4) is an aspheric plastic lens with negative focal power, and the object side surface of the fourth lens is a concave surface while the image side surface of the fourth lens is a convex surface;

be provided with aperture diaphragm (8) between first lens (1) and second lens (2), the rear of fourth lens (4) still is provided with:

the optical filter (5), the optical filter (5) is made of H-K9L;

a cover glass (6) integrated on a sensor (image sensor);

an image pickup element (7);

the ratio of the focal length of each lens to the total focal length of the system of the lens meets the following conditions:

0.76≤|f1/f|≤1.70；

0.97≤|f2/f|≤3.07；

0.56≤|f3/f|≤0.90；

0.70≤|f4/f|≤1.74；

2. The 6mm day and night high-definition glass-plastic hybrid prime lens according to claim 1, which is characterized in that: the focal length, refractive index and curvature radius of the first lens (1) to the fourth lens (4) respectively satisfy the following conditions:

3. The 6mm day and night high-definition glass-plastic hybrid prime lens according to claim 1, which is characterized in that:

IC/TTL≥0.29；

0.31≤OBFL/TTL≤0.44；

in the relation, the focal length of the lens optical system is f; the total length of the lens optical system is TTL; the optical rear intercept of the lens system is OBFL, namely the distance from one point, closest to the image surface, of the image side surface of the fourth lens (4) to the image surface; the 1/2.7 inch chip matched with the lens system has the full image height of IC.

4. The 6mm day and night high-definition glass-plastic hybrid prime lens according to claim 1, which is characterized in that: the aperture of the optical lens is F #, the F # is more than or equal to 1.90 and less than or equal to 2.40, and the total length of the lens optical system is TTL, and the TTL is less than or equal to 22.50 mm.

5. The 6mm day and night high-definition glass-plastic hybrid prime lens according to claim 1, which is characterized in that: the aspheric surfaces of the first lens (1), the third lens (3) and the fourth lens (4) can be defined by the following equation of even aspheric surfaces:

6. The 6mm day and night high-definition glass-plastic hybrid prime lens according to claim 1, which is characterized in that: the maximum distance between the third lens (3) and the fourth lens (4) on the central axis is not more than 0.38 mm.