CN111999860A

CN111999860A - Wide-angle imaging lens for video transmission

Info

Publication number: CN111999860A
Application number: CN202010920177.9A
Authority: CN
Inventors: 曹来书; 邓莉芬; 黄波; 黄立权
Original assignee: Xiamen Leading Optics Co Ltd
Current assignee: Xiamen Leading Optics Co Ltd
Priority date: 2020-09-04
Filing date: 2020-09-04
Publication date: 2020-11-27

Abstract

The invention discloses a wide-angle imaging lens for video transmission, which sequentially comprises a first lens, a second lens, a third lens and a fourth lens from an object side to an image side along an optical axis, wherein the first lens, the second lens and the third lens respectively comprise an object side surface facing the object side and allowing imaging light rays to pass and an image side surface facing the image side and allowing the imaging light rays to pass. The invention adopts nine lenses along the direction from the object side to the image side, and makes the imaging field angle of the lens large and the application range large by correspondingly designing each lens; the resolution of the lens reaches 4K, the imaging quality is ensured, the light transmission F/2.3 is about, the image edge illumination is uniform, the imaging signal-to-noise ratio is ultrahigh, and the development of later-stage image optimization algorithm is facilitated; the blue-violet side chromatic aberration is corrected, and the phenomena of blue-violet side and the like can not occur during imaging; the lens is low in manufacturing cost, easy to use in large-scale mass production, capable of improving product competitiveness, small in temperature drift, capable of offsetting the influence of temperature disturbance on imaging quality, and clear in picture without defocusing.

Description

Wide-angle imaging lens for video transmission

Technical Field

The invention relates to the technical field of lenses, in particular to a wide-angle imaging lens for video transmission.

Background

With the rapid development of global economy, the demand of people on video transmission is increasing day by day, and the video transmission is widely applied to various departments such as government, military, medical treatment, teaching and the like, thereby providing reliable guarantee for the rapid development of global economy.

However, the imaging lens currently applied to the field of video transmission has at least the following defects:

1. the horizontal FOV of the existing video transmission lens is more than 80-100 degrees, and when the existing video transmission lens is used in a large field, the imaging field angle is seriously insufficient.

2. The existing video transmission lens has the defects of about two million pixels, high image noise point, poor imaging quality and difficult post-algorithm processing.

3. The existing video transmission lens generally has blue-violet side chromatic aberration due to the wide-angle low-distortion design, which affects the image quality.

Disclosure of Invention

The invention aims to provide a wide-angle imaging lens for video transmission, which has the advantages of large imaging field angle, good imaging quality and no blue-violet chromatic aberration during imaging.

In order to achieve the purpose, the invention adopts the following technical scheme:

a wide-angle imaging lens for video transmission sequentially comprises a first lens, a second lens, a third lens and a fourth lens from an object side to an image side along an optical axis, wherein the first lens, the second lens and the third lens respectively comprise an object side surface facing the object side and allowing imaging light rays to pass and an image side surface facing the image side and allowing the imaging light rays to pass;

the first lens element with negative refractive index has a convex object-side surface and a concave image-side surface;

the second lens element with negative refractive index has a convex object-side surface and a concave image-side surface;

the third lens element with negative refractive index has a convex object-side surface and a concave image-side surface;

the fourth lens element with negative refractive index has a convex object-side surface and a concave image-side surface;

the fifth lens element with positive refractive index has a convex object-side surface and a convex image-side surface;

the sixth lens element with negative refractive index has a planar object-side surface and a concave image-side surface;

the seventh lens element with positive refractive index has a convex object-side surface and a convex image-side surface;

the eighth lens element with positive refractive index has a convex object-side surface and a convex image-side surface;

the ninth lens element with positive refractive index has a concave object-side surface and a convex image-side surface;

the image side surface of the fourth lens is mutually glued with the object side surface of the fifth lens, the image side surface of the sixth lens is mutually glued with the object side surface of the seventh lens, the first lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are glass spherical lenses, the second lens, the third lens, the eighth lens and the ninth lens are plastic high-order even-order aspheric lenses, and a diaphragm is arranged between the fifth lens and the sixth lens.

Further, the focal length range of the first to ninth lenses satisfies the following condition:

-6< f1< -14, -6< f2< -4, -25< f3<23, 8< f4< -10, 4< f5<6, -11< f6< -9, -47< f7< -45, 6< f8<8, 12< f9<14, wherein f1, f2, f3, f4, f5, f6, f7, f8, f9 are the focal length values of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, respectively.

Further, the ratio of the focal length of the first, fourth, fifth, sixth and seventh lenses to the focal length of the lens satisfies the following relationship:

-8< (f1/f) < -6, 3< (f4/f) <5, 2< (f5/f) <3, -6< (f6/f) < -4, -24< (f7/f) < -22, wherein f is the focal length of the lens, and f1, f4, f5, f6, f7 are the focal length values of the first lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens, respectively.

the eighth lens element with positive refractive index has a convex object-side surface and a concave image-side surface;

the first lens element with negative refractive index has a concave object-side surface and a concave image-side surface;

the second lens element with negative refractive index has a concave object-side surface and a concave image-side surface;

the third lens element with positive refractive index has a concave object-side surface and a convex image-side surface;

the fourth lens element with positive refractive index has a convex object-side surface and a concave image-side surface;

the sixth lens element with positive refractive index has a concave object-side surface and a convex image-side surface;

the seventh lens element with negative refractive index has a concave object-side surface and a convex image-side surface;

the image side surface of the sixth lens and the object side surface of the seventh lens are mutually glued, the third, fourth, fifth, sixth and seventh lenses are glass spherical lenses, the first, second, eighth and ninth lenses are plastic high-order even-order aspheric lenses, and a diaphragm is arranged between the fourth lens and the fifth lens.

the third lens element with positive refractive index has a convex object-side surface and a convex image-side surface;

the fourth lens element with positive refractive index has a concave object-side surface and a convex image-side surface;

the fifth lens element with positive refractive index has a convex object-side surface and a concave image-side surface;

the seventh lens element with negative refractive index has a concave object-side surface and a concave image-side surface;

the image side surface of the fifth lens and the object side surface of the sixth lens are mutually glued, the first lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are glass spherical lenses, the second lens, the third lens, the eighth lens and the ninth lens are plastic high-order even-order aspheric lenses, and a diaphragm is arranged between the fourth lens and the fifth lens.

The focusing mechanism is arranged on the base and is in transmission connection with the lens frame, and the focusing mechanism is used for adjusting the distance between the lens frame and the base so as to perform focusing.

Further, the focusing mechanism includes adjustable ring, gear train and motor, the top of base upwards extends and forms a connecting cylinder, be equipped with on the connecting cylinder the light trap, the adjustable ring includes interior link, external ring and outer ring gear, interior link and picture frame outer wall looks spiro union, external ring and connecting cylinder inner wall looks spiro union, just the screw thread pitch of interior link is greater than the screw thread pitch of external ring, outer ring gear is connected with the gear train transmission, the motor install in on the base, the output of motor passes through the gear train with the outer ring gear cooperation of adjustable ring with output torque.

Furthermore, the focusing mechanism further comprises a permanent magnet and a Hall sensor, the permanent magnet is fixedly arranged on the lens frame and moves up and down along with the lens frame, and the Hall sensor is arranged on the base and used for sensing the position of the permanent magnet so as to position the lens barrel.

After adopting the technical scheme, compared with the background technology, the invention has the following advantages:

1. the invention adopts nine lenses along the direction from the object side to the image side, and the horizontal FOV of the lens is between 110 degrees and 120 degrees through correspondingly designing each lens, so that the imaging field angle is large, and the application range is wide; the resolution ratio of the lens reaches 4K, the imaging quality is guaranteed, the light transmission F/2.3 is about, the image edge illumination is uniform, the imaging signal-to-noise ratio is ultrahigh, and the development of later-stage image optimization algorithms is facilitated.

2. The invention adopts the design of multiple aspheric surfaces, corrects the blue-violet side chromatic aberration on the premise of ensuring wide-angle low-distortion imaging, avoids the phenomena of blue-violet side and the like during imaging, simultaneously adopts the glass-plastic mixed design, not only evenly spreads the cost of the plastic aspheric surfaces, but also ensures that the manufacturing cost of the lens is low, is easy for large-scale mass production and use, improves the product competitiveness, has small temperature drift, can offset the influence of temperature disturbance on the imaging quality, has clear pictures without defocusing, and meets the use requirements of most video conferences and other severe environments.

3. According to the invention, the gear set is driven by the output torque of the motor, the adjusting ring is driven by the gear set, the screw thread screwing depth of the lens frame is driven by the rotation of the adjusting ring to change, the optical automatic focusing process is realized, the noise is low, the image jitter is small, the image is clear and is not defocused, and meanwhile, the position of the lens frame is detected by the Hall sensor, so that the reduction of the focusing precision caused by the step loss accumulation of gear transmission is prevented.

Drawings

FIG. 1 is a perspective view of one embodiment of the present invention;

FIG. 2 is a second perspective view of the present invention;

FIG. 3 is a cross-sectional view of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 at A;

FIG. 5 is a bottom view of the present invention;

FIG. 6 is a diagram of an optical path of an imaging lens according to an embodiment of the present invention;

FIG. 7 is a graph of MTF under visible light of an imaging lens according to an embodiment of the present invention;

FIG. 8 is a defocus graph of an imaging lens in visible light according to an embodiment of the present invention;

FIG. 9 is a longitudinal aberration diagram of an imaging lens under visible light according to an embodiment of the present invention;

FIG. 10 is a diagram illustrating curvature of field and distortion of an imaging lens under visible light according to an embodiment of the present invention;

FIG. 11 is a diagram illustrating an optical path of an imaging lens according to a second embodiment of the present invention;

fig. 12 is a graph of MTF under visible light of the imaging lens according to the second embodiment of the present invention;

FIG. 13 is a defocus graph of an imaging lens in a second embodiment of the present invention under visible light;

FIG. 14 is a longitudinal aberration diagram of the imaging lens of the second embodiment of the present invention under visible light;

FIG. 15 is a diagram illustrating curvature of field and distortion of an imaging lens under visible light according to a second embodiment of the present invention;

FIG. 16 is a diagram illustrating an optical path of an imaging lens according to a third embodiment of the present invention;

fig. 17 is a graph of MTF of the imaging lens in the third embodiment of the present invention under visible light;

FIG. 18 is a defocus graph of an imaging lens in a third embodiment of the present invention under visible light;

FIG. 19 is a longitudinal aberration diagram of the imaging lens of the third embodiment of the present invention under visible light;

FIG. 20 is a diagram illustrating curvature of field and distortion of an imaging lens under visible light according to a third embodiment of the present invention;

FIG. 21 is a diagram showing an optical path of an imaging lens according to a fourth embodiment of the present invention;

fig. 22 is a graph of MTF under visible light of the imaging lens according to the fourth embodiment of the present invention;

FIG. 23 is a defocus graph of an imaging lens in a fourth embodiment of the present invention under visible light;

FIG. 24 is a longitudinal aberration diagram of the imaging lens system under visible light in the fourth embodiment of the present invention;

FIG. 25 is a diagram of field curvature and distortion under visible light of an imaging lens according to a fourth embodiment of the present invention;

FIG. 26 is a diagram illustrating an optical path of an imaging lens according to a fifth embodiment of the present invention;

fig. 27 is a graph of MTF of the imaging lens in the fifth embodiment of the present invention under visible light;

FIG. 28 is a defocus graph of an imaging lens in the fifth embodiment of the present invention under visible light;

FIG. 29 is a longitudinal aberration diagram of the imaging lens of the fifth embodiment of the present invention under visible light;

fig. 30 is a field curvature and distortion diagram of the imaging lens under visible light in the fifth embodiment of the present invention.

Description of reference numerals:

a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a sixth lens 16, a seventh lens 17, an eighth lens 18, a ninth lens 19, and an aperture 110;

the base 2, the light hole 21 and the connecting cylinder 22;

a frame 3;

a lens barrel 4;

the focusing mechanism 5, the adjusting ring 51, the inner ring 511, the outer ring 512, the outer gear ring 513, the gear set 52, the motor 53 and the Hall sensor 54.

Detailed Description

To further illustrate the various embodiments, the invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. Those skilled in the art will appreciate still other possible embodiments and advantages of the present invention with reference to these figures. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The invention will now be further described with reference to the accompanying drawings and detailed description.

In the present specification, the term "a lens element having a positive refractive index (or a negative refractive index)" means that the paraxial refractive index of the lens element calculated by the gauss theory is positive (or negative). The term "object-side (or image-side) of a lens" is defined as the specific range of imaging light rays passing through the lens surface. The determination of the surface shape of the lens can be performed by the judgment method of a person skilled in the art, i.e., by the sign of the curvature radius (abbreviated as R value). The R value may be commonly used in optical design software, such as Zemax or CodeV. The R value is also commonly found in lens data sheets (lens sheets) of optical design software. When the R value is positive, the object side is judged to be a convex surface; and when the R value is negative, judging that the object side surface is a concave surface. On the contrary, regarding the image side surface, when the R value is positive, the image side surface is judged to be a concave surface; when the R value is negative, the image side surface is judged to be convex.

In conjunction with fig. 1 to 5, the present invention discloses a wide-angle imaging lens for video transmission, which includes, in order from an object side to an image side along an optical axis, a first lens element 11 to a ninth lens element 19, where the first lens element 11 to the ninth lens element 19 respectively include an object side surface facing the object side and allowing an imaging light to pass therethrough and an image side surface facing the image side and allowing the imaging light to pass therethrough.

The utility model provides a wide angle imaging lens for video transmission, still includes base 2, picture frame 3, lens cone 4 and focusing mechanism 5, set up a light trap 21 in base 2, light trap 21 is used for holding picture frame 3, lens cone 4 is installed in picture frame 3, first lens 11 to ninth lens 19 are installed in lens cone 4, focusing mechanism 5 sets up on base 2 to be connected with the transmission of picture frame 3, adjust the distance of picture frame 3 relative base 2 in order to focus through focusing mechanism 5.

The focusing mechanism 5 comprises an adjusting ring 51, a gear set 52 and a motor 53, the top of the base 2 extends upwards to form a connecting cylinder 22, a light hole 21 is formed in the connecting cylinder 22, the adjusting ring 51 comprises an inner ring 511, an outer ring 512 and an outer gear ring 513, the inner ring 511 is in threaded connection with the outer wall of the lens frame 3, the outer ring 512 is in threaded connection with the inner wall of the connecting cylinder 22, the thread pitch of the inner ring 511 is larger than that of the outer ring 512, the outer gear ring 513 is in transmission connection with the gear set 52, the motor 53 is installed on the base 2, and the output end of the motor 53 is matched with the outer gear ring 513 of the adjusting ring 51 through the gear set 52 to. After the motor 53 outputs torque to drive the gear set 52, the gear set 52 drives the adjusting ring 51, and the adjusting ring 51 rotates to drive the thread screwing depth of the lens frame 3 to change, so that the optical automatic focusing process is realized.

The focusing mechanism 5 further includes a permanent magnet (not shown in the figure) fixed on the frame 3 and moving up and down together with the frame, and a hall sensor 54 provided on the base 2 for sensing the position of the permanent magnet to position the lens barrel 4. When the lens frame 3 moves, the lens frame 3 and the hall sensor 54 move (displace) relatively, and at this time, the hall sensor 54 generates different signals, that is, the different signals are used to detect the position of the lens. Because there is the multiple clearance step-out in gear drive, the step-out accumulation can appear after long-time motion, detects the position of picture frame 3 through the position of hall sensor 54 response permanent magnet to the position of camera lens can be rectified, prevents to lead to the precision decline of focusing because of gear drive step-out accumulation.

The wide-angle imaging lens of the present invention will be described in detail below with specific embodiments.

Example one

In conjunction with fig. 6 to 10, the present embodiment discloses a wide-angle imaging lens for video transmission, which includes, in order from an object side to an image side along an optical axis, a first lens element 11 to a ninth lens element 19, where the first lens element 11 to the ninth lens element 19 respectively include an object side surface facing the object side and allowing the imaging light to pass therethrough and an image side surface facing the image side and allowing the imaging light to pass therethrough;

the first lens element 11 has a negative refractive index, and has a convex object-side surface and a concave image-side surface;

the second lens element 12 with negative refractive index has a convex object-side surface and a concave image-side surface;

the third lens element 13 with negative refractive index has a convex object-side surface and a concave image-side surface;

the fourth lens element 14 with negative refractive index has a convex object-side surface and a concave image-side surface;

the fifth lens element 15 with positive refractive index has a convex object-side surface and a convex image-side surface;

the sixth lens element 16 with negative refractive index has a planar object-side surface and a concave image-side surface;

the seventh lens element 17 with positive refractive index has a convex object-side surface and a convex image-side surface;

the eighth lens element 18 with positive refractive index has a convex object-side surface and a convex image-side surface;

the ninth lens element 19 with positive refractive power has a concave object-side surface and a convex image-side surface;

the image-side surface of the fourth lens element 14 and the object-side surface of the fifth lens element 15 are cemented with each other, the image-side surface of the sixth lens element 16 and the object-side surface of the seventh lens element 17 are cemented with each other, the first, fourth, fifth, sixth and seventh lens elements are glass spherical lens elements, the second, third, eighth and ninth lens elements are plastic high-order even-order aspheric lens elements, and a diaphragm 110 is disposed between the fifth lens element 15 and the sixth lens element 16, but in other embodiments, the diaphragm 110 may be disposed at other suitable positions.

The focal length range of the first lens 11 to the ninth lens 19 satisfies the following condition:

-6< f1< -14, -6< f2< -4, -25< f3<23, 8< f4< -10, 4< f5<6, -11< f6< -9, -47< f7< -45, 6< f8<8, 12< f9<14, wherein f1, f2, f3, f4, f5, f6, f7, f8, f9 are the focal length values of the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, the fifth lens 15, the sixth lens 16, the seventh lens 17, the eighth lens 18, the ninth lens 19, respectively.

The ratio of the focal length of the first, fourth, fifth, sixth and seventh lenses to the focal length of the lens satisfies the following relationship:

-8< (f1/f) < -6, 3< (f4/f) <5, 2< (f5/f) <3, -6< (f6/f) < -4, -24< (f7/f) < -22, wherein f is the focal length of the lens, and f1, f4, f5, f6, f7 are the focal length values of the first lens 11, the fourth lens 14, the fifth lens 15, the sixth lens 16, and the seventh lens 17, respectively.

Detailed optical data of this embodiment are shown in table 1.

Table 1 detailed optical data of example one

Surface of		Caliber size (diameter)	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									0	Shot object surface		Infinite size
1	First lens	15.302	11.832	0.960	H-LAF50B	1.772501	49.6135	-15.74
									2		10.792	5.795	2.370
3	Second lens	10.502	23.553	0.925	ZEONEX_K26R	1.535037	55.7107	-5.47
									4		7.346	2.574	1.608
5	Third lens	7.120	9.253	0.780	EP6000	1.640	23.529	-24.97
									6		5.806	5.681	1.618
7	Fourth lens	5.769	28.057	0.600	H-ZPK1A	1.618	63.406	-9.16
									8	Fifth lens element	5.551299	4.681	3.810	H-ZLAF92	2.003	28.317	3.63
9		4.504	-9.977	1.324
									10		1.909	Infinite size	0.013
11	Sixth lens element	1.923	Infinite size	1.910	FDS18	1.945945	17.9843	-3.88
									12	Seventh lens element	3.053	3.707	1.640	FCD515	1.592824	68.6244	4.59
13		4.119	-8.640	0.070
									14	Eighth lens element	5.545	7.557	1.555	ZEONEX_K26R	1.535037	55.7107	7.61
15		5.645	-8.259	0.127
									16	Ninth lens	5.673	-24.763	1.290	ZEONEX_K26R	1.535037	55.7107	13.05
17		5.905	-5.558	0.100
									18	Cover glass	6.010	Infinite size	0.800	H-K9L	1.516797	64.2124
19		6.070	Infinite size	2.700
									20	Image plane	6.409	Infinite size

Fig. 6 is a schematic diagram of an optical path of an optical imaging lens in this embodiment. Referring to fig. 7, it can be seen that when the spatial frequency of the lens reaches 160lp/mm, the full-field transfer function image is still greater than 35%, and the imaging quality is excellent. Referring to fig. 8, the defocus amount of the visible light in fig. 8 is less than 9 μm, and the confocal optical system has a confocal function and can be used for both day and night. Referring to fig. 9, it can be seen that the longitudinal aberration is less than ± 0.07mm, the color reduction is good, and the blue-violet phenomenon is not obvious. Referring to fig. 10, it can be seen that the distortion is less than-5%, the image is less in shape, the image is more accurate to restore the image, and the imaging quality is high.

Example two

As shown in fig. 11 to 15, in this embodiment, the surface convexoconcave and the refractive index of each lens element are substantially the same as those of the first embodiment, and only the surface convexoconcave of the eighth lens element is not uniform.

The detailed optical data of this embodiment are shown in table 2.

Table 2 detailed optical data of example one

Surface of		Caliber size (diameter)	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									0	Shot object surface		Infinite size
1	First lens	8.722	11.889	1.148	H-LAF50B	1.772501	49.6135	-17.34
									2		5.545	6.043	2.274
3	Second lens	5.134	25.000	1.371	K26R	1.535011	55.6341	-5.59
									4		5.024	2.628	2.170
5	Third lens	3.694	14.013	0.900	EP6000	1.640	23.529	-18.20
									6		7.000	6.225	1.199				-9.11
7	Fourth lens	7.000	41.125	0.600	H-ZPK5	1.593	68.525
									8	Fifth lens element	4.3	4.760	3.051	TAFD65	2.051	26.942
9		4.931	-10.430	1.425				3.45
									10		5.200	Infinite size	0.013				-3.66
11	Sixth lens element	5.387	Infinite size	1.560	H-ZF88	1.945958	17.9439
									12	Seventh lens element	5.963	3.494	1.578	H-ZPK5	1.592807	68.5250	4.39
13		6.052	-8.591	0.100
									14	Eighth lens element	6.621	9.006	1.448	K26R	1.535011	55.6341	7.70
15		7.189	-7.209	0.162
									16	Ninth lens	7.758	-24.886	1.599	K26R	1.535011	55.6341	11.51
17		8.327	-5.060	0.100
									18	Cover glass	8.895	Infinite size	0.800	H-K9L	1.516797	64.2124
19		9.464	Infinite size	2.703
									20	Image plane	10.033	Infinite size

Fig. 11 is a schematic diagram of an optical path of an optical imaging lens in this embodiment. Referring to fig. 12, it can be seen that when the spatial frequency of the lens reaches 160lp/mm, the full-field transfer function image is still greater than 30%, and the imaging quality is excellent. Referring to fig. 13, the defocus amount of the visible light in fig. 13 is less than 9 μm, and the confocal optical system has a confocal function and can be used for both day and night. Referring to fig. 14, it can be seen that the longitudinal aberration is less than ± 0.05mm, the color reduction is good, and the blue-violet phenomenon is not obvious. Referring to fig. 15, it can be seen that the distortion is less than-5%, the image is less in shape, the image is more accurate to restore the image, and the imaging quality is high.

EXAMPLE III

As shown in fig. 16 to 20, the optical parameters of the lens elements of the present embodiment and the first embodiment are different, such as surface roughness, refractive index, surface curvature radius, and lens thickness.

the eighth lens element 18 with positive refractive index has a convex object-side surface and a concave image-side surface;

The detailed optical data of this embodiment are shown in table 3.

Table 3 detailed optical data of example one

Surface of		Caliber size (diameter)	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									0	Shot object surface		Infinite size
1	First lens	16.057	12.680	1.000	H-LAF50B	1.772501	49.6135	-15.87
									2		11.248	6.029	2.371
3	Second lens	11.015	25.000	1.300	K26R	1.535011	55.6341	-5.98
									4		7.532	2.794	1.783
5	Third lens	7.134	9.958	0.880	EP6000	1.640	23.529	-26.60
									6		5.742	6.081	1.565
7	Fourth lens	5.698	88.761	0.600	H-LAK50A	1.652	58.416	-7.37
									8	Fifth lens element	5.483099	4.557	2.813	H-ZLAF92	2.003	28.317	3.46
9		4.800	-10.339	1.605
									10		1.888	Infinite size	0.013
11	Sixth lens element	1.901	Infinite size	1.818	H-ZF88	1.945958	17.9439	-4.20
									12	Seventh lens element	3.940	4.017	1.548	H-ZPK5	1.592807	68.5250	4.37
13		3.940	-6.285	0.100
									14	Eighth lens element	4.782	9.703	0.824	K26R	1.535011	55.6341	-305.84
15		5.165	8.889	0.324
									16	Ninth lens	6.019	5.045	2.056	K26R	1.535011	55.6341	5.50
17		6.051	-6.095	0.100
									18	Cover glass	6.117	Infinite size	0.800	H-K9L	1.516797	64.2124
19		6.172	Infinite size	2.704
									20	Image plane	6.453	Infinite size

Fig. 16 is a schematic diagram of an optical path of an optical imaging lens in this embodiment. Referring to fig. 17, it can be seen that when the spatial frequency of the lens reaches 160lp/mm, the full-field transfer function image is still greater than 40%, and the imaging quality is excellent. Referring to fig. 18, the defocus amount of the visible light in fig. 18 is less than 9 μm, and the confocal optical system has a confocal function and can be used for both day and night. Referring to fig. 19, it can be seen that the longitudinal aberration is less than ± 0.07mm, the color reduction is good, and the blue-violet phenomenon is not obvious. Referring to fig. 20, it can be seen that the distortion is less than-5%, the image is less in shape, the image is more accurate to restore the image, and the imaging quality is high.

Example four

As shown in fig. 21 to 25, the optical parameters of the lens elements of this embodiment and the first embodiment are different, such as surface roughness, refractive index, surface curvature radius, and lens thickness.

The first lens element 11 has negative refractive index, and has a concave object-side surface and a concave image-side surface;

the second lens element 12 has negative refractive index, and has a concave object-side surface and a concave image-side surface;

the third lens element 13 with positive refractive index has a concave object-side surface and a convex image-side surface;

the fourth lens element 14 with positive refractive index has a convex object-side surface and a concave image-side surface;

the sixth lens element 16 with positive refractive index has a concave object-side surface and a convex image-side surface;

the seventh lens element 17 with negative refractive index has a concave object-side surface and a convex image-side surface;

the image-side surface of the sixth lens element 16 and the object-side surface of the seventh lens element 17 are cemented with each other, the third, fourth, fifth, sixth and seventh lens elements are glass spherical lens elements, the first, second, eighth and ninth lens elements are plastic high-order even-order aspheric lens elements, and a stop 110 is disposed between the fourth lens element 14 and the fifth lens element 15, but the stop 110 may be disposed at other suitable positions in other embodiments.

The detailed optical data of this embodiment are shown in table 4.

Table 4 detailed optical data of example one

Surface of		Caliber size (diameter)	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									0	Shot object surface		Infinite size
1	First lens	16.094	-33.389	1.674	EP6000	1.639730	23.5289	-6.21
									2		8.304	4.635	2.680
3	Second lens	7.896	-18.126	0.653	EP6000	1.639730	23.5289	-7.38
									4		5.997	6.528	2.469
5	Third lens	5.864	-8.527	2.964	H-ZF3	1.717	29.510	17.80
									6		6.110	-5.872	0.174
7	Fourth lens	4.800	5.593	1.309	H-ZF88	1.946	17.944	10.60
									8		3.987566	11.069	1.859
9		1.753	Infinite size	0.267
									10	Fifth lens element	2.043	34.760	1.612	H-FK61	1.496998	81.5947	9.62
11		2.919	-5.475	0.099
									12	Sixth lens element	3.078	-18.691	1.761	H-LAK53B	1.754998	52.3374	3.08
13	Seventh lens element	3.524	-2.160	0.536	H-ZF88	1.945958	17.9439	-2.51
									14		4.399	-24.655	0.077
15	Eighth lens element	5.122	11.515	1.214	ZEONEX_F	1.534611	56.0721	7.30
									16		5.222	-5.712	0.093
17	Ninth lens	5.983	-14.287	1.636	ZEONEX_F	1.534611	56.0721	13.19
									18		6.042	-4.920	0.093
19	Cover glass	6.112	Infinite size	0.800	H-K9L	1.516797	64.2124
									20		6.175	Infinite size	1.754
21	Image plane	6.446	Infinite size

Fig. 21 is a diagram of an optical path of the optical imaging lens in this embodiment. Referring to fig. 22, it can be seen that when the spatial frequency of the lens reaches 160lp/mm, the full-field transfer function image is still greater than 35%, and the imaging quality is excellent. Referring to fig. 23, the defocus amount of the visible light in fig. 23 is less than 9 μm, and the confocal optical system has a confocal function and can be used for both day and night. Referring to fig. 24, it can be seen that the longitudinal aberration is less than ± 0.07mm, the color reduction is good, and the blue-violet phenomenon is not obvious. Referring to fig. 25, it can be seen that the distortion is less than-5%, the image is less in shape, the image is more accurate to restore the image, and the imaging quality is high.

EXAMPLE five

As shown in fig. 26 to 30, the optical parameters of the lens elements of the present embodiment and the first embodiment are different, such as surface roughness, refractive index, surface curvature radius, and lens thickness.

the third lens element 13 with positive refractive index has a convex object-side surface and a convex image-side surface;

the fourth lens element 14 with positive refractive index has a concave object-side surface and a convex image-side surface;

the fifth lens element 15 with positive refractive index has a convex object-side surface and a concave image-side surface;

the seventh lens element 17 with negative refractive index has a concave object-side surface and a concave image-side surface;

the image-side surface of the fifth lens element 15 and the object-side surface of the sixth lens element 16 are cemented with each other, the first, fourth, fifth, sixth and seventh lens elements are glass spherical lens elements, the second, third, eighth and ninth lens elements are plastic high-order even-order aspheric lens elements, and a diaphragm 110 is disposed between the fourth lens element 14 and the fifth lens element 15, but the diaphragm 110 may be disposed at other suitable positions in other embodiments.

The detailed optical data of this embodiment is shown in table 5.

Table 5 detailed optical data of example one

Surface of		Caliber size (diameter)	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									0	Shot object surface		Infinite size
1	First lens	12.723	10.321	1.000	H-ZLAF68N	1.883001	39.2253	-10.21
									2		8.629	4.623	2.331
3	Second lens	8.496	25.000	1.380	APL5015AL	1.544514	56.0033	-3.76
									4		5.869	1.872	2.491
5	Third lens	7.000	5.984	3.297	H-ZF52	1.847	23.787	4.71
									6		7.000	-9.507	0.160
7	Fourth lens	4.302	-6.437	2.780	EP6000	1.640	23.529	-42.09
									8		2.390	-9.839	0.100
9	Diaphragm surface	2.167	Infinite size	0.208
									10	Fifth lens element	5.000	5.601	0.872	H-ZF88	1.945958	17.9439	-9.38
11	Sixth lens element	3.200	3.204	1.586	H-FK61B	1.496998	81.5947	3.80
									12		3.200	-3.910	0.100
13	Seventh lens element	3.365	-10.287	0.600	H-ZLAF90	2.001	25.435	-4.64
									14		3.774	9.034	0.108
15	Eighth lens element	4.313	14.609	0.828	EP6000	1.639729	23.5288	45.64
									16		4.581	28.000	0.100
17	Ninth lens	5.413	4.552	2.759	APL5015AL	1.544514	56.0033	4.47
									18		5.721	-4.185	0.100
19	Cover glass	5.880	Infinite size	0.800	H-K9L	1.516797	64.2124
									20		5.964	Infinite size	2.601
21	Image plane	6.426	Infinite size

Fig. 26 is a schematic diagram of an optical path of an optical imaging lens in this embodiment. Referring to fig. 27, it can be seen that when the spatial frequency of the lens reaches 160lp/mm, the full-field transfer function image is still greater than 35%, and the imaging quality is excellent. Referring to fig. 28, the defocus amount of the visible light in fig. 28 is less than 9 μm, and the confocal optical system has a confocal function and can be used for both day and night. Referring to fig. 29, it can be seen that the longitudinal aberration is less than ± 0.07mm, the color reduction is good, and the blue-violet phenomenon is not obvious. Referring to fig. 30, it can be seen that the distortion is less than-5%, the image is less in shape, the image is more accurate to restore the image, and the imaging quality is high.

The size of the imaging surface of all the embodiments is 1/2.8 inches, the lens resolution can reach 4K (3864 multiplied by 2192), the imaging quality is guaranteed, the light passing rate is about F/2.3, the ultrahigh imaging signal-to-noise ratio is achieved, meanwhile, the overall static resolution and video resolution of the scheme are greatly improved, and the development of later-stage image optimization algorithms is greatly facilitated.

The focal length of all the embodiments is 1.8-2.0 mm, the HFOV is 110-120 degrees, the TTL is less than 25mm, and F/2.3 is about, so that the lens has the advantages of wide field of view, large light transmission, compact structure, strong practicability and the like.

Above all embodiments all adopt the design of multi-disc plastics even order aspheric surface, under the prerequisite of having guaranteed wide angle low distortion formation of image, blue purple limit colour difference has been corrected, phenomenons such as blue purple limit can not appear during the formation of image, can better correction senior aberration, promote image quality, simultaneously, adopt glass to mould mixed design, not only the cost is equallyd divide to the plastics aspheric surface, make the low in manufacturing cost of camera lens, easily extensive volume production is used, promote product competitiveness, and the temperature drift volume is little, can offset the influence of temperature disturbance to formation of image quality, the picture is clear not out of focus, can guarantee when the camera lens uses in-40 ℃ to 85 ℃ temperature interval, the picture is clear not out of focus, can satisfy the operation requirement under most video conferencing and other harsher environment.

The overall F-tan (theta) distortion of the lens of all the above embodiments is less than-5%, and the deformation amount corresponding to the image and the object is small.

All the lens structures of the above embodiments adopt AF focusing modules, so that a simple optical automatic focusing process can be realized, the noise is low, the image jitter is low, the image is clear and cannot be defocused, and the reduction of focusing precision caused by gear transmission step-out accumulation can be prevented.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A wide-angle imaging lens for video transmission, comprising: the imaging lens comprises 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 and the third lens are arranged along an optical axis from the object side to the image side;

2. A wide-angle imaging lens for video transmission as claimed in claim 1, wherein: the focal length ranges of the first to ninth lenses satisfy the following conditions:

3. A wide-angle imaging lens for video transmission as claimed in claim 2, wherein: the ratio of the focal length of the first, fourth, fifth, sixth and seventh lenses to the focal length of the lens satisfies the following relationship:

4. A wide-angle imaging lens for video transmission, comprising: the imaging lens comprises 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 and the third lens are arranged along an optical axis from the object side to the image side;

5. A wide-angle imaging lens for video transmission, comprising: the imaging lens comprises 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 and the third lens are arranged along an optical axis from the object side to the image side;

6. A wide-angle imaging lens for video transmission, comprising: the imaging lens comprises 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 and the third lens are arranged along an optical axis from the object side to the image side;

7. A wide-angle imaging lens for video transmission as claimed in claim 1, 4, 5 or 6, wherein: the focusing mechanism is arranged on the base and is in transmission connection with the lens frame, and the focusing mechanism is used for adjusting the distance between the lens frame and the base so as to focus.

8. A wide-angle imaging lens for video transmission as defined in claim 7, wherein: focusing mechanism includes adjustable ring, gear train and motor, the top of base upwards extends and forms a connecting cylinder, be equipped with on the connecting cylinder the light trap, the adjustable ring includes inner link, outer ring and outer ring gear, inner link and picture frame outer wall looks spiro union, outer ring and connecting cylinder inner wall looks spiro union, just the screw thread pitch of inner link is greater than the screw thread pitch of outer link, outer ring gear is connected with the gear train transmission, the motor install in on the base, the output of motor passes through the gear train cooperates with output torque with the outer ring gear of adjustable ring.

9. A wide-angle imaging lens for video transmission as defined in claim 8, wherein: the focusing mechanism further comprises a permanent magnet and a Hall sensor, the permanent magnet is fixedly arranged on the lens frame and moves up and down along with the lens frame, and the Hall sensor is arranged on the base and used for sensing the position of the permanent magnet so as to position the lens barrel.