CN209765147U

CN209765147U - Optical lens for ultra-wide-angle high-definition aerial photography instrument

Info

Publication number: CN209765147U
Application number: CN201920873683.XU
Authority: CN
Inventors: 史迎媛
Original assignee: Wendeng Chengjin Optical Co Ltd
Current assignee: Wendeng Chengjin Optical Co Ltd
Priority date: 2019-06-12
Filing date: 2019-06-12
Publication date: 2019-12-10
Anticipated expiration: 2029-06-12

Abstract

The utility model discloses an optical lens for an ultra-wide angle high definition aerial photography instrument, which comprises a diaphragm, an optical filter, a first lens group and a second lens group which are coaxially arranged between an object plane and an image plane; the diaphragm is arranged between the first lens group and the second lens group; the optical filter is arranged between the second lens group and the image surface; the first lens group and the second lens group are both wrapped in the lens barrel; the first lens group sequentially comprises a first lens, a second lens, a third lens and a fourth lens from an object plane to an image plane; the first lens is a meniscus lens with negative focal power and a convex surface facing to the object plane; the second lens is a plano-concave lens with negative focal power and a plane facing the object plane. The six spherical glass lenses of the utility model can realize large diagonal angle photographing angle; the image distortion is low, the image distortion is light, and the resolution and definition of the shot image can be effectively ensured under the condition of ensuring a larger field angle; the definition is high.

Description

optical lens for ultra-wide-angle high-definition aerial photography instrument

Technical Field

The utility model relates to an optical lens especially relates to an optical lens for super wide angle high definition aerial photography appearance.

Background

the optical lens is an essential component in a machine vision system, directly influences the quality of imaging quality and influences the realization and effect of an algorithm. Among wide-angle, standard, telephoto and wide-angle lenses, which are classified according to the size of the field of view, lenses having a particularly wide angle range (80 to 110 degrees) are called super wide-angle lenses. When the lens is applied to the aerial photography instrument, the aerial photography instrument is usually used in the air, and the height from the ground is higher, so that the lens for the aerial photography instrument has the functional requirements of clear imaging, wide shooting range, air veiling glare filtration and the like. However, the aerial photography instrument in the prior art is often not large enough in wide angle, limited in shooting range and prone to visual dead angles; and the definition of remote shooting is not enough and the image distortion is large, so that the image distortion is caused, and the aerial shooting effect is influenced.

SUMMERY OF THE UTILITY MODEL

In order to solve the weak point that above-mentioned technique exists, the utility model provides an optical lens for super wide angle high definition aerial photography appearance.

In order to solve the technical problem, the utility model discloses a technical scheme is: an optical lens for an ultra-wide-angle high-definition aerial photography instrument comprises a diaphragm, an optical filter, a first lens group and a second lens group, wherein the first lens group and the second lens group are coaxially arranged between an object plane and an image plane; the diaphragm is arranged between the first lens group and the second lens group; the optical filter is arranged between the second lens group and the image surface; the first lens group and the second lens group are both wrapped in the lens barrel;

The first lens group sequentially comprises a first lens, a second lens, a third lens and a fourth lens from an object plane to an image plane; the first lens is a meniscus lens with negative focal power and a convex surface facing to the object plane; the second lens is a plano-concave lens with negative focal power and the plane faces the object plane; the third lens and the fourth lens are both biconvex lenses with positive focal power; a first spacing ring is arranged between the first lens and the second lens; a second spacing ring is arranged between the third lens and the fourth lens;

the second lens group comprises a fifth lens and a sixth lens from the object plane to the image plane in sequence; the fifth lens and the sixth lens both have positive focal power, and the fifth lens and the sixth lens are mutually glued;

And a third spacing ring is arranged between the fourth lens and the fifth lens.

Further, the lens barrel and the first lens are fixed to each other by a pressing ring.

Furthermore, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all glass spherical lenses.

Further, the refractive index Nd of the first lens is 1.7< Nd <1.9, and the dispersion ratio Vd is 36< Vd < 39;

The refractive index Nd of the second lens is 1.7< Nd <1.9, and the dispersion ratio Vd is 36< Vd < 39;

The refractive index Nd of the third lens is 1.7< Nd <1.9, and the dispersion ratio Vd is 22< Vd < 24;

the refractive index Nd of the fourth lens is 1.6< Nd <1.8, and the dispersion ratio Vd is 49< Vd < 53;

The refractive index Nd of the fifth lens is 1.6< Nd <1.8, and the dispersion ratio Vd is 52< Vd < 55;

The refractive index Nd of the sixth lens is 1.8< Nd <2.0, and the dispersion Vd is 19< Vd < 22.

Further, the curved radii of the first lens are 16.4 and 4.75, respectively;

The curved surface radius of the second lens is infinite and 3.94 respectively;

The curved surface radius of the third lens is 17.5 and-17.5 respectively;

The curved surface radius of the fourth lens is respectively 6.06 and-15.67;

The radius of the curved surface of the fifth lens is 6.24;

The curved surface radii of the sixth lens are-2.3 and-25.06, respectively.

The six spherical glass lenses of the utility model can realize large diagonal angle photographing angle; the image distortion is low, the image distortion is light, and the resolution and definition of the shot image can be effectively ensured under the condition of ensuring a larger field angle; the definition is high.

drawings

fig. 1 is a system composition structure diagram of the present invention.

FIG. 2 is a diagram illustrating the path of light entering from the first embodiment.

FIG. 3 is a graph of MTF resolution in fields of 0.1 to 0.4 according to the first embodiment.

fig. 4 is a graph of MTF resolution in the 0.5 to 0.9 fields of view in the first embodiment.

FIG. 5 is a graph of MTF resolution at 1 field of view in the first embodiment.

Fig. 6 is a field curvature graph of the first embodiment.

Fig. 7 is a distortion graph of the first embodiment.

FIG. 8 is a dot-sequence diagram of the first embodiment.

In the figure: 1. a first lens; 2. a first spacer ring; 3. pressing a ring; 4. a lens barrel; 5. a second lens; 6. a third lens; 7. a second spacer ring; 8. a fourth lens; 9. a third spacer ring; 10. a fifth lens; 11. a sixth lens; 12. an optical filter; 13. an image plane; 14. an object surface; 15. and (4) a diaphragm.

Detailed Description

the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

The optical lens for the ultra-wide-angle high-definition aerial photography instrument shown in fig. 1 comprises a diaphragm 15, an optical filter 12, a first lens group and a second lens group, wherein the first lens group and the second lens group are coaxially arranged between an object plane 14 and an image plane 13; the first lens group comprises a first lens 1, a second lens 5, a third lens 6 and a fourth lens 8 in sequence from an object plane 14 to an image plane 13; the second lens group comprises a fifth lens 10 and a sixth lens 11 in sequence from an object plane 14 to an image plane 13; six glass spherical lenses have good aberration characteristic, and imaging quality is good, can also effectively reduce the processing degree of difficulty and manufacturing cost, and 6 lens mutually support and can realize that the angle of diagonal shooting is the biggest, and the maximum is 179 degrees.

The first lens 1 is a meniscus lens with negative focal power and a convex surface facing an object plane; the second lens 5 is a plano-concave lens with negative focal power and a plane facing the object plane; the first lens and the second lens can receive external light at a wide angle to the maximum extent and correct partial phase difference. The third lens 6 and the fourth lens 8 are both biconvex lenses with positive focal power; the fifth lens 10 and the sixth lens 11 are bonded to form a cemented lens having a positive refractive power; the third lens, the fourth lens, the fifth lens and the sixth lens converge the light of the first lens and the light of the second lens on the image plane, and the optical distortion level can be reduced by matching the first lens and the second lens, so that the imaging is clear.

A stop 15 is disposed between the first lens group and the second lens group to limit a light flux entering the second lens group through the first lens group; the optical filter 12 is arranged between the second lens group and the image plane 13, and can filter noise light outside a designed waveband, so that the imaging effect is optimal; the first lens group and the second lens group are wrapped in the lens barrel 4, the lens barrel provides supporting and protecting effects for the lenses, the lens barrel 4 and the first lens are fixed with each other through the pressing ring 3, and the pressing ring ensures that the lens groups are sealed and fixed in the lens barrel;

a first spacing ring 2 is arranged between the first lens and the second lens; a second spacing ring 7 is arranged between the third lens and the fourth lens; a third spacer ring 9 is arranged between the fourth lens 8 and the fifth lens 10. The spacing ring provides distance support for two adjacent lenses, so that the adjacent lenses have a space.

The first lens is a meniscus lens with a convex object side surface and a concave image side surface, and the curved surface radiuses of two side curved surfaces of the first lens are respectively 16.4 and 4.75; the refractive index Nd of the first lens 1 is 1.7< Nd <1.9, and the dispersion Vd is 36< Vd < 39. To increase the field angle of the wide-angle lens.

The object side surface of the second lens is a plane, the image side surface of the second lens is a concave surface, and the curved surface radiuses of the two surfaces of the second lens are respectively infinite and 3.94; the refractive index Nd of the second lens 5 is 1.7< Nd <1.9, and the dispersion Vd is 36< Vd < 39. The second lens is used for receiving the light of the first lens and scattering the light to the third lens.

the object side surface and the image side surface of the third lens are convex surfaces, and the curved surface radiuses of the convex surfaces at the two sides of the third lens are respectively 17.5 and-17.5; the refractive index Nd of the third lens 6 is 1.7< Nd <1.9, and the dispersion Vd is 22< Vd < 24. The second lens is used for correcting aberration generated by the light of the second lens and further dispersing the aberration to the fourth lens.

The object side surface and the image side surface of the fourth lens are convex surfaces, and the curved surface radiuses of the convex surfaces at the two sides of the fourth lens are respectively 6.06 and-15.67; the refractive index Nd of the fourth lens 8 is 1.6< Nd <1.8, and the dispersion Vd is 49< Vd < 53. Due to the difference of the radiuses of the curved surfaces on the two sides of the fourth lens, light rays are converged in the fourth lens and are transmitted to the fifth lens through the diaphragm.

the radius of the curved surface of the fifth lens is 6.24, the refractive index Nd is 1.6< Nd <1.8, and the dispersion ratio Vd is 52< Vd < 55; the curved surface radius of the sixth lens is-2.3 and-25.06 respectively, the refractive index Nd is 1.8< Nd <2.0, and the dispersion ratio Vd is 19< Vd < 22. The light has minimum chromatic aberration, and meanwhile, the spherical aberration is reduced, so that originally dispersed light is converged into one point and clearly imaged on an image surface through the optical filter.

The light rays pass through six lenses with different refractive indexes and different curved surface radiuses, so that the diagonal shooting angle of the lens is the largest, the image is the clearest, the shooting angle is 179 degrees, and the definition reaches three million pixels.

the optical properties of the present invention are further illustrated by a specific example.

In this embodiment, the specific optical parameters of the optical lens for the ultra-wide-angle high-definition aerial photography instrument are shown in table 1:

TABLE 1

surface name	surface type	radius of curved surface	Thickness of	glass material
					First lens	Spherical surface	16.4	1.2	NBFD10
	spherical surface	4.75	4
					Second lens	Spherical surface	infinite number of elements	1.5	NBFD10
	Spherical surface	3.94	1.32
					Third lens	spherical surface	17.5	1.75	FDS90
	Spherical surface	-17.5	4.9
					Fourth lens	Spherical surface	6.06	2.5	LAC10
	Spherical surface	-15.67	0.5
					Diaphragm	Spherical surface	Infinite number of elements	0.15
Fifth lens element	Spherical surface	6.24	2.5	LAC8
					Sixth lens element	Spherical surface	-2.3	1	FDS1
	spherical surface	-25.06	0.13
					Optical filter	Spherical surface	Infinite number of elements	0.4	BK7

the constitution has specifically been demonstrated in this embodiment the utility model discloses a surface type, curved surface radius, lens thickness and glass material isoparametric of six lenses and diaphragm, light filter.

Fig. 2 shows a path diagram of light entering from the present embodiment, and the optical performance of the present invention is verified through a specific experiment.

(1) The MTF (Modulation Transfer Function) resolution curves of the present embodiment in different FIELDs of view (FIELD) are shown in fig. 3, 4, and 5; FIG. 3 shows MTF resolution plots over 0.1 to 0.4 fields of view; FIG. 4 shows MTF resolution plots over 0.5 to 0.9 fields of view; fig. 5 shows the MTF resolution plot in the 1.0 field.

wherein, the abscissa: SPATIAL FREQUENCY IN CYCLES PER MILLIMETER represents the line pair/SPATIAL FREQUENCY per millimeter (lp/mm) and the ordinate represents the MTF value. The higher the curve, the better the imaging quality. Ordinate: in MODULUS OFTHEE OTF, OTF is fully called as: optical transfer function, refers to the optical transfer function. The ordinate here is: the optical modulation transfer function, i.e. the MTF we call. The embodiment shows better contrast ratio in the spatial frequency of 100lp/mm, which can show that the comprehensive resolution level of the embodiment is higher.

(2) graphs of curvature of field and distortion of the present embodiment are shown in fig. 6 and 7, respectively.

where the ordinate of both graphs is the normalized field of view, the abscissa of fig. 6: FIELD CURVATURE is FIELD CURVATURE in MICRONS, mm, fig. 7 abscissa: distorsion probability is PERCENT DISTORTION. In fig. 6, T and S represent the meridional and sagittal vectors, respectively, the distance between T and S represents the magnitude of astigmatism, the ordinate represents the field of view, the beamlet field curvature reflects the position change of the beamlet image point from the image plane at different field points, the primary beamlet field curvature is proportional to the square of the field of view, and its effect on the imaging is to make a planar object a curved image plane. Beamlet astigmatism reflects the axial distance separating the misalignment of the meridional and sagittal beamlet image points (or meridional and sagittal curvature image planes). Fig. 7 shows the field of view on the ordinate and the distortion percentage on the abscissa, and it can be seen that the astigmatism of this embodiment is relatively light, and can be controlled to be substantially within 20 μm, which reflects the relatively low optical distortion level of this embodiment to some extent. The optical distortion of the optical lens is-99% when the optical lens is used as an optical lens for ultra-wide-angle aerial photography, the optical distortion is low, and the optical performance is good.

(3) The optical system dot DIAGRAM (SPOT diameter) of the present embodiment at different FIELDs of view (FIELD) is shown in fig. 8.

Where RMS RADIUS represents the root mean square RADIUS, GEO RADIUS represents the geometric RADIUS, the Scale (SCALE BAR) is 40, and the principal RAY (CHIEF RAY) is used as the REFERENCE (REFERENCE). As shown in the figure, the imaging points under each field of view almost converge to an ideal point, indicating that the present embodiment has good imaging performance.

The utility model discloses compare the advantage that prior art has and do:

a. The maximum angle of diagonal photographing can be 179 degrees by six spherical glass lenses;

b. The image distortion is low, the image distortion is light, and the resolution and definition of the shot image can be effectively ensured under the condition of ensuring a larger field angle;

c. The definition is high and can reach three million pixels.

The above embodiments are not intended to limit the present invention, and the present invention is not limited to the above examples, and the technical personnel in the technical field are in the present invention, which can also belong to the protection scope of the present invention.

Claims

1. The utility model provides an optical lens for super wide angle high definition aerial photography appearance, includes diaphragm (15), light filter (12), its characterized in that: the zoom lens further comprises a first lens group and a second lens group which are coaxially arranged between the object plane (14) and the image plane (13); the diaphragm (15) is arranged between the first lens group and the second lens group; the optical filter (12) is arranged between the second lens group and the image plane (13); the first lens group and the second lens group are both wrapped in a lens barrel (4);

the first lens group comprises a first lens (1), a second lens (5), a third lens (6) and a fourth lens (8) from an object plane (14) to an image plane (13) in sequence; the first lens (1) is a meniscus lens with negative focal power and a convex surface facing an object plane; the second lens (5) is a plano-concave lens with negative focal power and a plane facing to the object plane; the third lens (6) and the fourth lens (8) are both biconvex lenses with positive focal power; a first spacing ring (2) is arranged between the first lens and the second lens; a second spacing ring (7) is arranged between the third lens and the fourth lens;

The second lens group comprises a fifth lens (10) and a sixth lens (11) in sequence from an object plane (14) to an image plane (13); the fifth lens (10) and the sixth lens (11) both have positive focal power, and the fifth lens (10) and the sixth lens (11) are mutually glued;

And a third spacing ring (9) is arranged between the fourth lens (8) and the fifth lens (10).

2. The optical lens for the ultra-wide angle high definition aerial photography instrument of claim 1, characterized in that: the lens cone (4) and the first lens are fixed with each other through the pressing ring (3).

3. the optical lens for the ultra-wide angle high definition aerial photography instrument of claim 1, characterized in that: the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all glass spherical lenses.

4. The optical lens for the ultra-wide-angle high-definition aerial photography instrument of claim 1 or 3, characterized in that: the refractive index Nd of the first lens (1) is 1.7< Nd <1.9, and the dispersion ratio Vd is 36< Vd < 39;

the refractive index Nd of the second lens (5) is 1.7< Nd <1.9, and the dispersion ratio Vd is 36< Vd < 39;

The refractive index Nd of the third lens (6) is 1.7< Nd <1.9, and the dispersion ratio Vd is 22< Vd < 24;

The refractive index Nd of the fourth lens (8) is 1.6< Nd <1.8, and the dispersion ratio Vd is 49< Vd < 53;

The refractive index Nd of the fifth lens (10) is 1.6< Nd <1.8, and the dispersion ratio Vd is 52< Vd < 55;

the refractive index Nd of the sixth lens (11) is 1.8< Nd <2.0, and the dispersion ratio Vd is 19< Vd < 22.

5. The optical lens for the ultra-wide-angle high-definition aerial photography instrument of claim 1 or 3, characterized in that: the curved surface radius of the first lens is 16.4 and 4.75 respectively;

The curved surface radius of the second lens is infinite and 3.94 respectively;

The curved surface radius of the third lens is 17.5 and-17.5 respectively;

The curved surface radius of the fourth lens is 6.06 and-15.67 respectively;

The radius of the curved surface of the fifth lens is 6.24;

The curved surface radius of the sixth lens is-2.3 and-25.06 respectively.