Detailed Description
For a better understanding of the invention, various aspects of the invention will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed description are merely illustrative of embodiments of the invention and are not intended to limit the scope of the invention in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.
It should be noted that in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Accordingly, a first lens discussed below may also be referred to as a second lens or a third lens without departing from the teachings of the present invention.
In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for convenience of explanation. In particular, the spherical or aspherical shape shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The figures are merely examples and are not drawn to scale.
Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position is not defined, it means that the lens surface is convex at least in the paraxial region, and if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side of the lens, and the surface of each lens closest to the imaging plane is referred to as the image side of the lens.
It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "containing," and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Furthermore, when a statement such as "at least one of the following" appears after a list of features that are listed, the entire listed feature is modified instead of modifying a separate element in the list. Furthermore, when describing embodiments of the invention, use of "may" means "one or more embodiments of the invention. Also, the term "exemplary" is intended to refer to an example or illustration.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.
The optical lens comprises a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an optical filter and protective glass in sequence from an object side to an image side.
In some embodiments, the first lens may have negative optical power, which facilitates reducing the tilt angle of incident light rays, thereby achieving effective sharing of the large field of view of the object. The object side surface and the image side surface of the first lens are concave surfaces, so that the effective working caliber of the first lens can be reduced, the problem that the caliber of a lens behind the optical lens is too large due to excessive divergence of light is avoided, the influence of coma aberration generated by the first lens on the optical lens can be reduced, and the imaging quality of the optical lens is improved.
In some embodiments, the second lens may have positive optical power, which is advantageous for converging light while reducing the angle of deflection of the light, and for smooth transition of the light profile. The object side surface of the second lens is a convex surface, and the image side surface is a concave surface, so that not only can the influence of field curvature generated by the second lens on the optical lens be reduced, but also the ghost energy of the light reflection of the object side surface of the second lens can be reduced, and the imaging quality of the optical lens can be improved.
In some embodiments, the third lens may have positive optical power, which is beneficial to converging light while reducing the light deflection angle, so that the light trend is smoothly transited. The object side surface of the third lens is a convex surface, so that vertical axis chromatic aberration caused by overlarge deflection angle of edge view field light rays in the process of transmitting the light rays from the second lens to the third lens can be effectively avoided, and the imaging quality of the optical lens is improved.
In some embodiments, the fourth lens may have negative focal power, which is beneficial to increasing the imaging area of the optical lens, reducing the difficulty in correcting chromatic aberration of the optical lens, and improving the imaging quality of the optical lens.
In some embodiments, the fifth lens may have positive optical power, which is beneficial to converging light while reducing the light deflection angle, so that the light trend is smoothly transited. The object side surface and the image side surface of the fifth lens are both convex surfaces, so that not only can the marginal view field light be converged, but also the converged light can smoothly enter the rear-end optical system, and the coma aberration generated by the fifth lens can be reduced, and the imaging quality of the optical lens is improved.
In some embodiments, the sixth lens may have negative optical power, which is beneficial to increasing the imaging area of the optical lens and improving the imaging quality of the optical lens. The object side surface of the sixth lens is a concave surface, the image side surface is a convex surface, the marginal view field light rays can be folded, various high-order aberration caused by excessive divergence of the light rays is avoided, and the imaging quality of the optical lens is improved.
In some embodiments, the seventh lens may have positive optical power, which is beneficial to suppressing the angle of incidence of the marginal field of view on the imaging surface, effectively transmitting more light beams to the imaging surface, and improving the imaging quality of the optical lens. The object side surface of the seventh lens is a convex surface, and the image side surface is a concave surface, so that the relative illumination of the edge view field is improved, the generation of dark angles is avoided, and the imaging quality of the optical lens is improved.
In some embodiments, the third lens and the fourth lens can be glued to form a glued lens, so that chromatic aberration of the optical lens can be effectively corrected, decentering sensitivity of the optical lens can be reduced, chromatic aberration of the optical lens can be balanced, imaging quality of the optical lens can be improved, assembly sensitivity of the optical lens can be reduced, difficulty in processing technology of the optical lens can be further reduced, and assembly yield of the optical lens can be improved.
In some embodiments, a diaphragm for limiting the light beam may be disposed between the first lens and the second lens, and the diaphragm may be disposed near the object side surface of the second lens, so that not only can the generation of ghost images of the optical lens be reduced, but also the range of the emergent light at the front end of the optical lens can be converged, and the caliber of the rear end of the optical lens can be reduced.
In some embodiments, the aperture value FNO of the optical lens satisfies FNO≤1.60. The range is satisfied, the large aperture characteristic is realized, and the definition of the image can be ensured in a low-light environment or at night.
In some embodiments, the maximum field angle FOV of the optical lens satisfies 100 ° < FOV. The wide-angle characteristic can be realized by meeting the range, so that more scene information can be acquired, and the requirement of large-range detection is met.
In some embodiments, the angle of incidence CRA of the maximum field angle chief ray of the optical lens on the image plane satisfies 18 ° < CRA <28 °. The above range is satisfied, so that a larger tolerance error range exists between the CRA of the optical lens and the CRA of the chip photosensitive element, and the adaptation capability of the optical lens to the image sensor is improved.
In some embodiments, the optical total length TTL and the effective focal length f of the optical lens satisfy 4.5< TTL/f <6.0. The length of the lens can be effectively limited by meeting the above range, and the miniaturization of the optical lens can be realized.
In some embodiments, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field angle satisfy 1.6< IH/f <1.9. The wide-angle characteristic can be realized by meeting the range, so that the requirement of large-range shooting is met, the large-image-plane characteristic can be realized, and the imaging quality of the optical lens is improved.
In some embodiments, the effective focal length f, the maximum field angle FOV, and the real image height IH of the optical lens corresponding to the maximum field angle satisfy 0.62< (IH/2)/(f×Tan (FOV/2)) <0.72. The method meets the above range, can control the distortion of the optical lens within a reasonable range, and is convenient for later restoration through a software algorithm.
In some embodiments, the maximum field angle FOV of the optical lens and the angle of incidence CRA of the maximum field angle chief ray on the image plane satisfy 1.8< (FOV/2)/CRA <2.8. The range is satisfied, so that the optical lens can realize a large field of view and simultaneously incident light rays can be emitted onto the image sensor at a proper angle, the photosensitive performance of the image sensor is further improved, and the imaging quality of the optical lens is improved.
In some embodiments, the effective focal length f of the optical lens and the focal length f 1 of the first lens satisfy-2.0 < f 1/f < -1.0. The range is satisfied, so that the first lens has proper negative focal power, the refraction angle change of incident light is mild, excessive aberration caused by excessively strong refraction change is avoided, more light rays enter the rear optical system, and the imaging quality of the optical lens is improved.
In some embodiments, the effective focal length f of the optical lens and the focal length f 2 of the second lens satisfy 3.0< f 2/f <5.0. The range is satisfied, the second lens has proper positive focal power, the light deflection angle is reduced while converging light rays is facilitated, the light rays are stably transited, and the imaging quality of the optical lens is improved.
In some embodiments, the effective focal length f of the optical lens and the focal length f 3 of the third lens satisfy 0<f 3/f <1.2. The range is satisfied, the third lens has proper positive focal power, the light deflection angle is reduced while converging light rays is facilitated, the light rays are stably transited, and the imaging quality of the optical lens is improved.
In some embodiments, the effective focal length f of the optical lens and the focal length f 4 of the fourth lens satisfy-1.5 < f 4/f <0. The range is satisfied, so that the fourth lens has proper negative focal power, the spherical aberration of the third lens is balanced, the chromatic aberration of the optical lens is corrected, and the imaging quality of the optical lens is improved.
In some embodiments, the effective focal length f of the optical lens and the focal length f 5 of the fifth lens satisfy 0<f 5/f <1.6. The range is satisfied, so that the fifth lens has proper positive focal power, various aberrations of the optical lens are balanced, and the imaging quality of the optical lens is improved.
In some embodiments, the effective focal length f of the optical lens and the focal length f 6 of the sixth lens satisfy-1.8 < f 6/f < -1.1. The range is satisfied, so that the sixth lens has proper negative focal power, the imaging area of the optical lens is increased, and the imaging quality of the optical lens is improved.
In some embodiments, the effective focal length f of the optical lens and the focal length f 7 of the seventh lens satisfy 1.5< f 7/f <3.0. The range is satisfied, so that the seventh lens has proper positive focal power, which is favorable for improving the light converging capacity of the marginal view field, and further improves the relative illumination of the optical lens.
In some embodiments, the maximum field angle FOV of the optical lens, the real image height IH corresponding to the maximum field angle, and the first lens object-side aperture D 1 satisfy 0.6< D 1/IH/Tan (FOV/2) <1.1. The front end caliber is small when the optical lens has a large field angle and a large image plane, and the miniaturization of the optical lens is facilitated.
In some embodiments, the sum of the total optical length TTL of the optical lens and the center thicknesses of the first lens to the seventh lens along the optical axis respectively ΣCT satisfies that 0.5< ΣCT/TTL <0.7. The total length of the optical lens can be effectively compressed by meeting the range, and the structural design and the production process of the optical lens are facilitated.
For better optical performance of the system, a plurality of aspheric lenses are adopted in the lens, and the shape of each aspheric surface of the optical lens meets the following equation:
Wherein z is the distance between the curved surface and the curved surface vertex in the optical axis direction, h is the distance between the optical axis and the curved surface, c is the curvature of the curved surface vertex, K is the quadric surface coefficient, A, B, C, D, E, F is the second, fourth, sixth, eighth, tenth and twelfth order surface coefficients respectively.
The invention is further illustrated in the following examples. In various embodiments, the thickness, radius of curvature, and material selection portion of each lens in the optical lens may vary, and for specific differences, reference may be made to the parameter tables of the various embodiments. The following examples are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following examples, and any other changes, substitutions, combinations or simplifications that do not depart from the gist of the present invention are intended to be equivalent substitutes within the scope of the present invention.
Example 1
Referring to fig. 1, a schematic structure of an optical lens according to embodiment 1 of the present invention is shown, where the optical lens includes, in order from an object side to an imaging plane along an optical axis, a first lens L1, a stop ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an optical filter G1, and a protective glass G2.
The first lens L1 has negative focal power, and both an object side surface S1 and an image side surface S2 of the first lens L are concave;
A diaphragm ST;
The second lens element L2 has positive refractive power, wherein an object-side surface S3 thereof is convex, and an image-side surface S4 thereof is concave;
the third lens element L3 has positive refractive power, and both an object-side surface S5 and an image-side surface S6 thereof are convex;
The fourth lens element L4 has negative refractive power, wherein an object-side surface S7 thereof is concave, and an image-side surface S8 thereof is convex;
The fifth lens element L5 has positive refractive power, and both an object-side surface S9 and an image-side surface S10 thereof are convex;
the sixth lens element L6 with negative refractive power has a concave object-side surface S11 and a convex image-side surface S12;
The seventh lens element L7 with positive refractive power has a convex object-side surface S13 and a concave image-side surface S14;
the optical filter G1, the object side surface S15 and the image side surface S16 of which are plane surfaces;
a cover glass G2 having an object side surface S17 and an image side surface S18 both of which are planar;
The imaging surface S19 is a plane;
the third lens L3 and the fourth lens L4 may be cemented to form a cemented lens.
The relevant parameters of each lens in the optical lens in example 1 are shown in tables 1-1.
TABLE 1-1
The surface profile parameters of the aspherical lens of the optical lens in example 1 are shown in tables 1 to 2.
TABLE 1-2
| Face number |
K |
A |
B |
C |
D |
E |
F |
| S3 |
-8.17E-01 |
0.00E+00 |
6.00E-04 |
-1.73E-05 |
1.06E-05 |
-1.09E-06 |
4.47E-08 |
| S4 |
1.32E+01 |
0.00E+00 |
7.02E-04 |
-3.64E-05 |
1.41E-05 |
-1.11E-06 |
3.97E-08 |
| S11 |
-3.98E+00 |
0.00E+00 |
2.24E-03 |
-5.39E-05 |
-1.10E-06 |
6.57E-08 |
-8.32E-10 |
| S12 |
-1.25E+01 |
0.00E+00 |
3.94E-03 |
-4.78E-05 |
3.38E-06 |
-1.05E-07 |
2.91E-09 |
| S13 |
-8.17E+00 |
0.00E+00 |
1.16E-03 |
-5.45E-05 |
3.54E-06 |
-6.98E-08 |
6.56E-10 |
| S14 |
8.53E+00 |
0.00E+00 |
-4.35E-04 |
5.82E-05 |
-5.71E-06 |
2.95E-07 |
-5.88E-09 |
Fig. 2 shows a field curvature graph of example 1, in which the degree of curvature of light rays of different wavelengths on a meridional image plane and a sagittal image plane is represented by the horizontal axis representing the amount of shift (unit: mm) and the vertical axis representing the half field angle (unit: °). From the graph, the field curvature of the meridian image plane and the sagittal image plane is controlled within +/-0.08 mm, which proves that the optical lens can well correct the field curvature.
Fig. 3 shows an F-Tan θ distortion graph of example 1, which represents F-Tan θ distortion of light rays of different wavelengths at different image heights on an imaging plane, with the horizontal axis representing F-Tan θ distortion (unit:%) and the vertical axis representing half field angle (unit: °). The graph shows that the F-Tan theta distortion of the optical lens is controlled to be uniform within +/-35%, which means that the F-Tan theta distortion of the optical lens is effectively controlled, and the optical lens is favorable for processing by a software algorithm in the later stage.
Fig. 4 shows a graph of relative illuminance for example 1, which represents relative illuminance values for different field angles on an imaging plane, with the horizontal axis representing half field angle (in: °), and the vertical axis representing relative illuminance (in:%). As can be seen from the figure, the relative illuminance value of the optical lens is still greater than 50% at the maximum half field angle, which indicates that the optical lens has better relative illuminance.
Fig. 5 shows a Modulation Transfer Function (MTF) graph of example 1, which represents a lens imaging modulation degree representing different spatial frequencies at each view field, the horizontal axis represents spatial frequency (unit: lp/mm), and the vertical axis represents MTF value. As can be seen from the graph, the MTF values of the embodiment are above 0.4 in the whole field of view, and in the range of 0-160 lp/mm, the MTF curve is uniformly and smoothly reduced in the process from the center to the edge field of view, and the imaging quality and detail resolution capability are good under the conditions of low frequency and high frequency.
Fig. 6 shows an axial aberration diagram of example 1, which represents aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents an axial aberration value (unit: μm), and the vertical axis represents a normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ±15 μm, which indicates that the optical lens can satisfactorily correct the axial aberration.
Fig. 7 shows a vertical axis color difference graph of example 1, which shows color differences at different image heights on an imaging plane for each wavelength with respect to a center wavelength (0.55 μm), with the horizontal axis showing a vertical axis color difference value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis showing a normalized field angle. As can be seen from the figure, the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within +/-4 mu m, which shows that the optical lens can excellently correct chromatic aberration of the edge view field and the secondary spectrum of the whole image surface.
Example 2
Referring to fig. 8, a schematic structural diagram of an optical lens provided in embodiment 2 of the present invention is shown, and the optical lens includes, in order from an object side to an imaging surface along an optical axis, a first lens L1, a stop ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an optical filter G1 and a protective glass G2.
The first lens L1 has negative focal power, and both an object side surface S1 and an image side surface S2 of the first lens L are concave;
A diaphragm ST;
The second lens element L2 has positive refractive power, wherein an object-side surface S3 thereof is convex, and an image-side surface S4 thereof is concave;
the third lens element L3 has positive refractive power, and both an object-side surface S5 and an image-side surface S6 thereof are convex;
the fourth lens element L4 has negative focal power, and both the object-side surface S7 and the image-side surface S8 thereof are concave surfaces;
The fifth lens element L5 has positive refractive power, and both an object-side surface S9 and an image-side surface S10 thereof are convex;
the sixth lens element L6 with negative refractive power has a concave object-side surface S11 and a convex image-side surface S12;
The seventh lens element L7 with positive refractive power has a convex object-side surface S13 and a concave image-side surface S14;
the optical filter G1, the object side surface S15 and the image side surface S16 of which are plane surfaces;
a cover glass G2 having an object side surface S17 and an image side surface S18 both of which are planar;
The imaging surface S19 is a plane;
the third lens L3 and the fourth lens L4 may be cemented to form a cemented lens.
The relevant parameters of each lens in the optical lens in example 2 are shown in table 2-1.
TABLE 2-1
The surface profile parameters of the aspherical lens of the optical lens in example 2 are shown in tables 2-2.
TABLE 2-2
| Face number |
K |
A |
B |
C |
D |
E |
F |
| S3 |
-2.20E-01 |
0.00E+00 |
7.01E-04 |
-6.92E-06 |
7.97E-06 |
-5.78E-07 |
2.26E-08 |
| S4 |
3.27E+01 |
0.00E+00 |
5.83E-04 |
2.27E-05 |
8.66E-07 |
1.56E-07 |
-7.68E-09 |
| S11 |
-7.82E+00 |
0.00E+00 |
2.18E-03 |
-9.34E-05 |
9.04E-07 |
1.89E-08 |
-4.47E-10 |
| S12 |
-1.05E+02 |
0.00E+00 |
4.53E-03 |
-5.42E-05 |
5.90E-07 |
1.69E-07 |
-4.75E-09 |
| S13 |
-7.92E+00 |
0.00E+00 |
1.03E-03 |
-1.38E-05 |
6.67E-07 |
5.78E-08 |
-1.52E-09 |
| S14 |
3.46E+00 |
0.00E+00 |
-6.83E-04 |
9.59E-06 |
-2.79E-06 |
1.77E-07 |
-6.22E-09 |
Fig. 9 shows a field curvature graph of example 2, in which the degree of curvature of light rays of different wavelengths on a meridional image plane and a sagittal image plane is represented by the horizontal axis representing the amount of shift (unit: mm) and the vertical axis representing the half angle of view (unit: °). From the graph, the field curvature of the meridian image plane and the sagittal image plane is controlled within +/-0.04 mm, which shows that the optical lens can excellently correct the field curvature.
Fig. 10 shows an F-Tan θ distortion graph of example 2, which represents F-Tan θ distortion of light rays of different wavelengths at different image heights on an imaging plane, with the horizontal axis representing F-Tan θ distortion (unit:%) and the vertical axis representing half field angle (unit: °). The graph shows that the F-Tan theta distortion of the optical lens is controlled to be uniform within +/-35%, which means that the F-Tan theta distortion of the optical lens is effectively controlled, and the optical lens is favorable for processing by a software algorithm in the later stage.
Fig. 11 shows a graph of relative illuminance for example 2, which shows relative illuminance values for different field angles on an imaging plane, with the horizontal axis representing half field angle (in: °), and the vertical axis representing relative illuminance (in:%). As can be seen from the figure, the relative illuminance value of the optical lens at the maximum half field angle is still greater than 60%, indicating that the optical lens has good relative illuminance.
Fig. 12 shows a Modulation Transfer Function (MTF) graph of example 2, which represents a lens imaging modulation degree representing different spatial frequencies at each view field, the horizontal axis represents spatial frequency (unit: lp/mm), and the vertical axis represents MTF value. As can be seen from the graph, the MTF values of the embodiment are above 0.4 in the whole field of view, and in the range of 0-160 lp/mm, the MTF curve is uniformly and smoothly reduced in the process from the center to the edge field of view, and the imaging quality and detail resolution capability are good under the conditions of low frequency and high frequency.
Fig. 13 shows an axial aberration diagram of example 2, which represents aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents an axial aberration value (unit: μm), and the vertical axis represents a normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ±10μm, indicating that the optical lens can excellently correct the axial aberration.
Fig. 14 shows a vertical axis color difference graph of example 2, which shows color differences at different image heights on an imaging plane for each wavelength with respect to a center wavelength (0.55 μm), with the horizontal axis showing a vertical axis color difference value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis showing a normalized field angle. As can be seen from the figure, the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within +/-3 mu m, which shows that the optical lens can excellently correct chromatic aberration of the marginal field of view and the secondary spectrum of the whole image surface.
Example 3
Referring to fig. 15, a schematic structural diagram of an optical lens provided in embodiment 3 of the present invention is shown, and the optical lens includes, in order from an object side to an imaging surface along an optical axis, a first lens L1, a stop ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an optical filter G1, and a cover glass G2.
The first lens L1 has negative focal power, and both an object side surface S1 and an image side surface S2 of the first lens L are concave;
A diaphragm ST;
The second lens element L2 has positive refractive power, wherein an object-side surface S3 thereof is convex, and an image-side surface S4 thereof is concave;
the third lens element L3 has positive refractive power, and both an object-side surface S5 and an image-side surface S6 thereof are convex;
the fourth lens element L4 has negative focal power, and both the object-side surface S7 and the image-side surface S8 thereof are concave surfaces;
The fifth lens element L5 has positive refractive power, and both an object-side surface S9 and an image-side surface S10 thereof are convex;
the sixth lens element L6 with negative refractive power has a concave object-side surface S11 and a convex image-side surface S12;
The seventh lens element L7 with positive refractive power has a convex object-side surface S13 and a concave image-side surface S14;
the optical filter G1, the object side surface S15 and the image side surface S16 of which are plane surfaces;
a cover glass G2 having an object side surface S17 and an image side surface S18 both of which are planar;
The imaging surface S19 is a plane;
the third lens L3 and the fourth lens L4 may be cemented to form a cemented lens.
The relevant parameters of each lens in the optical lens in example 3 are shown in table 3-1.
TABLE 3-1
The surface profile parameters of the aspherical lens of the optical lens in example 3 are shown in table 3-2.
TABLE 3-2
| Face number |
K |
A |
B |
C |
D |
E |
F |
| S3 |
9.91E-02 |
0.00E+00 |
6.15E-04 |
-1.86E-05 |
9.82E-06 |
-8.08E-07 |
3.17E-08 |
| S4 |
6.61E+00 |
0.00E+00 |
6.52E-04 |
-2.74E-05 |
8.97E-06 |
-6.49E-07 |
1.31E-08 |
| S11 |
-6.71E+00 |
0.00E+00 |
3.28E-03 |
-1.23E-04 |
-7.75E-07 |
1.46E-07 |
-3.00E-09 |
| S12 |
-4.11E+01 |
0.00E+00 |
5.33E-03 |
2.12E-05 |
-6.21E-06 |
5.41E-07 |
-6.76E-09 |
| S13 |
-5.76E+00 |
0.00E+00 |
1.66E-03 |
-8.72E-05 |
3.52E-06 |
-3.03E-08 |
3.36E-09 |
| S14 |
8.11E-01 |
0.00E+00 |
-2.03E-03 |
1.11E-04 |
-1.83E-05 |
1.07E-06 |
-3.08E-08 |
Fig. 16 shows a field curvature graph of example 3, in which the degree of curvature of light rays of different wavelengths on a meridional image plane and a sagittal image plane is represented by the horizontal axis representing the amount of shift (unit: mm) and the vertical axis representing the half angle of view (unit: °). From the graph, the field curvature of the meridian image plane and the sagittal image plane is controlled within +/-0.04 mm, which shows that the optical lens can excellently correct the field curvature.
Fig. 17 shows an F-Tan θ distortion graph of example 3, which represents F-Tan θ distortion at different image heights on an imaging plane for light rays of different wavelengths, with the horizontal axis representing F-Tan θ distortion (unit:%) and the vertical axis representing half field angle (unit: °). The graph shows that the F-Tan theta distortion of the optical lens is controlled to be uniform within +/-32%, which means that the F-Tan theta distortion of the optical lens is effectively controlled, and the optical lens is favorable for processing by a software algorithm in the later stage.
Fig. 18 shows a graph of relative illuminance of example 3, which represents relative illuminance values at different view angles on an imaging plane, with the horizontal axis representing half view angle (unit: °), and the vertical axis representing relative illuminance (unit:%). As can be seen from the figure, the relative illuminance value of the optical lens is still greater than 50% at the maximum half field angle, which indicates that the optical lens has better relative illuminance.
Fig. 19 shows a Modulation Transfer Function (MTF) graph of example 3, which represents a lens imaging modulation degree representing different spatial frequencies at each view field, the horizontal axis represents spatial frequency (unit: lp/mm), and the vertical axis represents MTF value. As can be seen from the graph, the MTF values of the embodiment are above 0.4 in the whole field of view, and in the range of 0-160 lp/mm, the MTF curve is uniformly and smoothly reduced in the process from the center to the edge field of view, and the imaging quality and detail resolution capability are good under the conditions of low frequency and high frequency.
Fig. 20 shows an axial aberration diagram of example 3, which represents aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents an axial aberration value (unit: μm), and the vertical axis represents a normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ±20μm, which indicates that the optical lens can satisfactorily correct the axial aberration.
Fig. 21 shows a vertical axis color difference graph of example 3, which shows color differences at different image heights on an imaging plane for each wavelength with respect to a center wavelength (0.55 μm), with the horizontal axis showing a vertical axis color difference value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis showing a normalized field angle. As can be seen from the figure, the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within +/-3 mu m, which shows that the optical lens can excellently correct chromatic aberration of the marginal field of view and the secondary spectrum of the whole image surface.
Example 4
Referring to fig. 22, a schematic structural diagram of an optical lens provided in embodiment 4 of the present invention is shown, and the optical lens includes, in order from an object side to an imaging surface along an optical axis, a first lens L1, a stop ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an optical filter G1 and a cover glass G2.
The first lens L1 has negative focal power, and both an object side surface S1 and an image side surface S2 of the first lens L are concave;
A diaphragm ST;
The second lens element L2 has positive refractive power, wherein an object-side surface S3 thereof is convex, and an image-side surface S4 thereof is concave;
the third lens element L3 has positive refractive power, and both an object-side surface S5 and an image-side surface S6 thereof are convex;
the fourth lens element L4 has negative focal power, and both the object-side surface S7 and the image-side surface S8 thereof are concave surfaces;
The fifth lens element L5 has positive refractive power, and both an object-side surface S9 and an image-side surface S10 thereof are convex;
The sixth lens element L6 with negative refractive power has a concave object-side surface S11 and a convex image-side surface S12, the seventh lens element L7 with positive refractive power has a convex object-side surface S13 and a concave image-side surface S14, and the optical filter G1 has a plane object-side surface S15 and an image-side surface S16;
a cover glass G2 having an object side surface S17 and an image side surface S18 both of which are planar;
The imaging surface S19 is a plane;
the third lens L3 and the fourth lens L4 may be cemented to form a cemented lens.
The relevant parameters of each lens in the optical lens in example 4 are shown in table 4-1.
TABLE 4-1
The surface profile parameters of the aspherical lens of the optical lens in example 4 are shown in table 4-2.
TABLE 4-2
Fig. 23 shows a field curvature graph of example 4, in which the degree of curvature of light rays of different wavelengths on a meridional image plane and a sagittal image plane is shown, the horizontal axis represents the amount of shift (unit: mm), and the vertical axis represents the half angle of view (unit: °). From the graph, the field curvature of the meridian image plane and the sagittal image plane is controlled within +/-0.04 mm, which shows that the optical lens can excellently correct the field curvature.
Fig. 24 shows an F-Tan θ distortion graph of example 4, in which F-Tan θ distortion at different image heights on an imaging plane is represented by light rays of different wavelengths, the horizontal axis represents F-Tan θ distortion (unit:%) and the vertical axis represents half field angle (unit: °). The graph shows that the F-Tan theta distortion of the optical lens is controlled to be uniform within +/-36%, which means that the F-Tan theta distortion of the optical lens is effectively controlled, and the optical lens is favorable for processing by a software algorithm in the later stage.
Fig. 25 shows a graph of relative illuminance of example 4, which represents relative illuminance values at different view angles on an imaging plane, with the horizontal axis representing half view angle (unit: °), and the vertical axis representing relative illuminance (unit:%). As can be seen from the figure, the relative illuminance value of the optical lens at the maximum half field angle is still greater than 60%, indicating that the optical lens has good relative illuminance.
Fig. 26 shows a Modulation Transfer Function (MTF) graph of example 4, which represents the lens imaging modulation degree representing different spatial frequencies at each view field, the horizontal axis represents the spatial frequency (unit: lp/mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF values of the embodiment are above 0.4 in the whole field of view, and in the range of 0-160 lp/mm, the MTF curve is uniformly and smoothly reduced in the process from the center to the edge field of view, and the imaging quality and detail resolution capability are good under the conditions of low frequency and high frequency.
Fig. 27 shows an axial aberration diagram of example 4, which represents aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents an axial aberration value (unit: μm), and the vertical axis represents a normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ±20μm, which indicates that the optical lens can satisfactorily correct the axial aberration.
Fig. 28 shows a vertical axis color difference graph of example 4, which shows color differences at different image heights on an imaging plane for each wavelength with respect to a center wavelength (0.55 μm), with the horizontal axis showing a vertical axis color difference value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis showing a normalized field angle. As can be seen from the figure, the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within +/-4 mu m, which shows that the optical lens can excellently correct chromatic aberration of the edge view field and the secondary spectrum of the whole image surface.
Referring to table 5, the optical characteristics corresponding to the above embodiments include the effective focal length f, the total optical length TTL, the f-number FNO, the real image height IH, the field angle FOV and the numerical value corresponding to each condition in the above embodiments.
TABLE 5
| Parameters and conditions |
Example 1 |
Example 2 |
Example 3 |
Example 4 |
| f(mm) |
5.32 |
5.32 |
5.08 |
5.40 |
| TTL(mm) |
26.17 |
28.56 |
27.85 |
27.39 |
| FNO |
1.60 |
1.60 |
1.60 |
1.60 |
| IH(mm) |
9.25 |
9.25 |
9.25 |
9.25 |
| EPD(mm) |
3.33 |
3.32 |
3.18 |
3.38 |
| FOV(°) |
106 |
106 |
106 |
106 |
| CRA(°) |
20.85 |
25.32 |
26.44 |
20.30 |
| TTL/f |
4.92 |
5.37 |
5.48 |
5.07 |
| IH/f |
1.74 |
1.74 |
1.82 |
1.71 |
| (IH/2)/(f×Tan(FOV/2)) |
0.65 |
0.66 |
0.69 |
0.64 |
| (FOV/2)/CRA |
2.54 |
2.09 |
2.00 |
2.61 |
| f1/f |
-1.14 |
-1.43 |
-1.75 |
-1.22 |
| f2/f |
3.16 |
3.59 |
4.67 |
3.44 |
| f3/f |
1.02 |
1.03 |
1.00 |
0.97 |
| f4/f |
-1.28 |
-1.15 |
-1.14 |
-1.21 |
| f5/f |
1.51 |
1.54 |
1.53 |
1.50 |
| f6/f |
-1.37 |
-1.58 |
-1.59 |
-1.39 |
| f7/f |
1.79 |
2.44 |
2.69 |
1.94 |
| D1/IH/Tan(FOV/2) |
0.68 |
0.95 |
1.02 |
0.80 |
| ∑CT/TTL |
0.68 |
0.60 |
0.52 |
0.66 |
In summary, the optical lens of the embodiment of the invention realizes the effects of large field of view, large aperture and miniaturization by reasonably matching the lens shape and focal power combination among the lenses.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.