CN114236773B - Optical lens - Google Patents
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- CN114236773B CN114236773B CN202111645437.7A CN202111645437A CN114236773B CN 114236773 B CN114236773 B CN 114236773B CN 202111645437 A CN202111645437 A CN 202111645437A CN 114236773 B CN114236773 B CN 114236773B
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- 239000011521 glass Substances 0.000 claims description 9
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- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/18—Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
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Abstract
The invention provides an optical lens. The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens which is a meniscus lens having positive optical power; a second lens which is a meniscus lens having negative optical power; a third lens which is a meniscus lens having positive optical power; a fourth lens which is a meniscus lens having negative optical power; a fifth lens which is a meniscus lens having positive optical power; a sixth lens which is a biconvex lens having positive optical power; a seventh lens which is a meniscus lens having positive optical power; a light filter; an imaging surface. The invention solves the problems of large target surface, large aperture, high resolution and miniaturization of the optical lens in the prior art, which are difficult to be simultaneously considered.
Description
Technical Field
The invention relates to the technical field of optical imaging, in particular to an optical lens.
Background
Due to the high-speed development of automatic driving in recent years, the optical lens for vehicle use is increasingly applied in the automatic driving field, especially in the aspects of vehicle-mounted lenses, laser radars and the like, and besides the requirements of high pixel and small volume, other requirements of the optical lens are also increasingly increased, such as large angle of view, long focal length, small FNO, high illumination, small distortion and the like, and other performances which are particularly required according to different applications are required. But some properties are often difficult to achieve simultaneously.
At present, the field of laser radar is developed gradually, and some problems still exist in the optical lens in the prior art, for example: the imaging target surface of the optical fixed focus lens in the prior art is smaller, most of the imaging target surface is concentrated at 1/2.7 inch, and the current use requirement cannot be met. There are also some optical fixed focus lenses in the market, which have smaller aperture and F numbers of F1.6 and above. Some manufacturers also provide an optical lens, and the number of lenses of the optical lens is too large, so that the imaging quality is effectively improved, but the overall size of the optical lens is increased, and the miniaturization requirement cannot be met.
That is, the optical lens in the prior art has a problem that it is difficult to achieve both a large target surface, a large aperture, a high resolution and miniaturization.
Disclosure of Invention
The invention mainly aims to provide an optical lens, which solves the problems that the optical lens in the prior art has large target surface, large aperture, high resolution and miniaturization are difficult to be compatible.
In order to achieve the above object, the present invention provides an optical lens comprising, in order from an object side to an image side along an optical axis: a first lens which is a meniscus lens having positive optical power; a second lens which is a meniscus lens having negative optical power; a third lens which is a meniscus lens having positive optical power; a fourth lens which is a meniscus lens having negative optical power; a fifth lens which is a meniscus lens having positive optical power; a sixth lens which is a biconvex lens having positive optical power; a seventh lens which is a meniscus lens having positive optical power; a light filter; an imaging surface.
Further, the optical lens further includes an aperture stop disposed between the third lens and the fourth lens.
Further, the focal length f1 of the first lens, the total focal length f of the optical lens, and the field angle FOV of the optical lens satisfy: 5.5.ltoreq.f 1/f. Tan (FOV) 6.0.
Further, the first lens, the third lens, the fourth lens, the fifth lens and the seventh lens are all glass spherical lenses, and the second lens and the sixth lens are glass spherical lenses or glass aspherical lenses.
Further, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; and/or the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface.
Further, the center radius of curvature R4 of the image side of the second lens and the center radius of curvature R5 of the object side of the third lens satisfy: (R5-R4)/(R5+R4) is less than or equal to 1.3.
Further, the focal length f3 of the third lens and the focal length f5 of the fifth lens satisfy: f3/f5 is less than or equal to 0.63.
Further, the focal length f1 of the first lens satisfies: f1 is less than or equal to 23mm; the focal length f6 of the sixth lens satisfies: f6 is less than or equal to 29mm.
Further, abbe number V of the first lens d1 The method meets the following conditions: v (V) d1 Less than or equal to 33; abbe number V of the third lens d3 The method meets the following conditions: v (V) d3 ≥16。
Further, refractive index N of the fifth lens d5 The method meets the following conditions: n (N) d5 Less than or equal to 1.67; refractive index N of seventh lens d7 The method meets the following conditions: n (N) d7 ≤1.72。
By applying the technical scheme of the invention, the optical lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an optical filter and an imaging surface from an object side to an image side along an optical axis. The first lens is a meniscus lens with positive focal power; the second lens is a meniscus lens with negative focal power; the third lens is a meniscus lens with positive focal power; the fourth lens is a meniscus lens with negative focal power; the fifth lens is a meniscus lens with positive focal power; the sixth lens is a biconvex lens with positive focal power; the seventh lens is a meniscus lens having positive optical power.
The optical power and the surface shape of each lens are reasonably configured, so that the imaging capability is improved, the high-resolution performance is ensured, and the optical lens can realize better distortion control and excellent imaging characteristics. Meanwhile, the optical lens can still ensure better working performance and better imaging quality under the extreme temperature environment state. The seven lenses are adopted in the optical lens, the number of the lenses is small, the overall length of the system of the optical lens is small, the size of the optical lens is reduced, and miniaturization is guaranteed. In addition, the optical lens of the application realizes large target surface, low cost, large aperture and high resolution.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:
fig. 1 is a schematic view showing the structure of an optical lens according to a first embodiment of the present invention;
FIG. 2 shows a graph of the optical transfer function MTF of the optical lens of FIG. 1 at normal temperature in the visible light band;
FIG. 3 shows a field curvature diagram of the optical lens of FIG. 1 in the visible light band;
FIG. 4 shows a distortion diagram of the optical lens of FIG. 1 in the visible light band;
FIG. 5 shows a lateral fan of the optical lens of FIG. 1 in the visible light band;
FIG. 6 shows a point-column diagram of the optical lens of FIG. 1 in the visible light band;
fig. 7 is a schematic structural diagram of an optical lens according to a second embodiment of the present invention;
FIG. 8 shows a graph of the optical transfer function MTF of the optical lens of FIG. 7 at ambient conditions in the visible light band;
FIG. 9 shows a field curvature diagram of the optical lens of FIG. 7 in the visible light band;
FIG. 10 shows a distortion plot of the optical lens of FIG. 7 in the visible light band;
FIG. 11 shows a lateral fan view of the optical lens of FIG. 7 in the visible light band;
fig. 12 shows a point diagram of the optical lens in fig. 7 in the visible light band.
Wherein the above figures include the following reference numerals:
l1, a first lens; l2, a second lens; l3, a third lens; STOP and aperture STOP; l4, a fourth lens; l5, a fifth lens; l6, sixth lens; l7, seventh lens; l8, an optical filter; IMA, imaging plane.
Detailed Description
It should be noted that, in the case of no conflict, the embodiments and features in 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.
It is noted that all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless otherwise indicated.
In the present invention, unless otherwise indicated, terms of orientation such as "upper, lower, top, bottom" are used generally with respect to the orientation shown in the drawings or with respect to the component itself in the vertical, upright or gravitational direction; also, for ease of understanding and description, "inner and outer" refers to inner and outer relative to the profile of each component itself, but the above-mentioned orientation terms are not intended to limit the present invention.
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, then the lens surface is convex at least in the paraxial region; 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 near the object side becomes the object side of the lens, and the surface of each lens near the image side is called the image side of the lens. The determination of the surface shape in the paraxial region can be performed by a determination method by a person skilled in the art by positive or negative determination of the concave-convex with R value (R means the radius of curvature of the paraxial region, and generally means the R value on a lens database (lens data) in optical software). In the object side surface, when the R value is positive, the object side surface is judged to be convex, and when the R value is negative, the object side surface is judged to be concave; in the image side, the concave surface is determined when the R value is positive, and the convex surface is determined when the R value is negative. The left side is the object side and the right side is the image side. The object side is the surface facing the object side, and the image side is the surface facing the image side.
The invention provides an optical lens, which aims to solve the problems that the optical lens in the prior art has a large target surface, a large aperture, high resolution and miniaturization are difficult to take into account at the same time.
As shown in fig. 1 to 12, the optical lens includes, in order from an object side to an image side along an optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an optical filter, and an imaging plane. The first lens is a meniscus lens with positive focal power; the second lens is a meniscus lens with negative focal power; the third lens is a meniscus lens with positive focal power; the fourth lens is a meniscus lens with negative focal power; the fifth lens is a meniscus lens with positive focal power; the sixth lens is a biconvex lens with positive focal power; the seventh lens is a meniscus lens having positive optical power.
The optical power and the surface shape of each lens are reasonably configured, so that the imaging capability is improved, the high-resolution performance is ensured, and the optical lens can realize better distortion control and excellent imaging characteristics. Meanwhile, the optical lens can still ensure better working performance and better imaging quality under the extreme temperature environment state. The seven lenses are adopted in the optical lens, the number of the lenses is small, the overall length of the system of the optical lens is small, the size of the optical lens is reduced, and miniaturization is guaranteed. In addition, the optical lens of the application realizes large target surface, low cost, large aperture and high resolution.
It should be noted that the imaging target surface of the optical lens can support 1/1.8 inch at most, effectively realize high resolution and ensure imaging quality, and can adapt to the environment of-40-120 ℃ for use so as to meet the requirements at different temperatures. Maximum support of imaging surface size of the optical lens
The sensor (CCD/CMOS) camera of the device meets the requirement of high resolution of the device. The mechanical total length of the optical lens is not more than 38mm, and the miniaturization requirement is met. The full-field MTF value of the optical lens reaches more than 0.5 under the condition of 100lp/mm, and has excellent imaging characteristics. The focal power distribution of each lens in the optical lens is reasonable, the shape of each lens is convenient to process, and low cost is ensured. The aperture of the optical lens is larger, the F number is 1.4, and the optical lens is particularly suitable for monitoring under the low-illumination condition and the requirement of a laser radar lens.
Specifically, the optical lens further includes an aperture stop disposed between the third lens and the fourth lens. Through setting up aperture stop for aperture stop can effectively be to the receipts of the light in getting into the optical lens, effectively plan the light trend, is favorable to reducing the bore of lens simultaneously, makes more compacter between each lens of optical lens, in order to guarantee miniaturization.
Specifically, the focal length f1 of the first lens, the total focal length f of the optical lens and the field angle FOV of the optical lens satisfy: 5.5.ltoreq.f 1/f. Tan (FOV) 6.0.
Specifically, the first lens, the third lens, the fourth lens, the fifth lens and the seventh lens are all glass spherical lenses, and the second lens and the sixth lens are glass spherical lenses or glass aspherical lenses. By limiting the material of each lens, it is advantageous to ensure low cost. By selecting an aspherical lens, the curvature is continuously changed from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better radius of curvature characteristic, and has advantages of improving distortion aberration and improving astigmatic aberration. By adopting the aspherical lens, aberration occurring at the time of imaging can be eliminated as much as possible, thereby improving imaging quality.
In one embodiment of the present application, the object side surface of the second lens element is convex, and the image side surface of the second lens element is concave; the object side surface of the third lens is concave, and the image side surface of the third lens is convex.
Specifically, the center radius of curvature R4 of the image side surface of the second lens element and the center radius of curvature R5 of the object side surface of the third lens element satisfy: (R5-R4)/(R5+R4) is less than or equal to 1.3.
Specifically, the focal length f3 of the third lens and the focal length f5 of the fifth lens satisfy: f3/f5 is less than or equal to 0.63.
Specifically, the focal length f1 of the first lens satisfies: f1 is less than or equal to 23mm; the focal length f6 of the sixth lens satisfies: f6 is less than or equal to 29mm.
Specifically, the Abbe number V of the first lens d1 The method meets the following conditions: v (V) d1 Less than or equal to 33; abbe number V of the third lens d3 The method meets the following conditions: v (V) d3 ≥16。
Specifically, the refractive index N of the fifth lens d5 The method meets the following conditions: n (N) d5 Less than or equal to 1.67; refractive index N of seventh lens d7 The method meets the following conditions: n (N) d7 ≤1.72。
Specific embodiments of the optical lens of the present application are described in detail below with reference to the accompanying drawings.
Example 1
As shown in fig. 1 to 6, a first embodiment of the present application is described. Fig. 1 is a schematic structural diagram of an optical lens according to a first embodiment of the present application.
As shown in fig. 1, the optical lens sequentially includes, from an object side to an image side: a first lens L1, a second lens L2, a third lens L3, an aperture STOP, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an optical filter L8, and an imaging plane IMA.
In the first embodiment, the curvature radius R, the center thickness Tc, the refractive index Nd, the abbe number Vd, and the cone coefficient k of each lens of the optical lens satisfy the conditions shown in table 1:
TABLE 1
As can be seen from the above table, the object side surface of the first lens element is convex, and the image side surface is concave; the object side surface of the second lens is a convex surface, and the image side surface is a concave surface; the object side surface of the third lens is a concave surface, and the image side surface is a convex surface; the object side surface of the fourth lens is a concave surface, and the image side surface is a convex surface; the object side surface of the fifth lens is a concave surface, and the image side surface is a convex surface; the object side surface of the sixth lens is a convex surface, and the image side surface is a convex surface; the seventh lens element has a convex object-side surface and a concave image-side surface.
In the schematic structural diagram of the optical lens shown in fig. 1, the mirror numbers in table 1 are the numbers of the lenses from left to right. The third lens L3 is an aspherical lens, and the sixth lens L6 is an aspherical lens.
The aspherical cone coefficients can be defined by the following aspherical formula, but are not limited to the following representation:
wherein Z is the axial sagittal height of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitting sphere, and the numerical value is the reciprocal of the curvature radius; k is a fitting cone coefficient; a-F are 4 th, 6 th, 8 th, 10 th, 12 th, 14 th order polynomial coefficients of the aspherical polynomial. The following table 2 gives the higher order coefficients A, B, C, D, E, F that can be used for the aspherical lens in embodiment one.
| Mirror number | A | B | C | | E | F | |
| 3 | 2.026E-05 | 6.162E-07 | -4.913E-08 | -3.519E-09 | -8.118E-11 | 1.441E-11 | |
| 4 | -7.283E-05 | -6.966E-06 | -8.622E-07 | -8.247E-08 | -6.021E-09 | 1.847E-09 | |
| 12 | 2.506E-06 | -2.052E-07 | -4.620E-09 | 4.583E-11 | 2.116E-12 | 4.704E-15 | |
| 13 | 9.557E-07 | -7.234E-08 | -1.331E-09 | -7.962E-11 | -6.313E-13 | 5.734E-14 |
TABLE 2
It should be noted that the data listed in the foregoing table are preferred data of the present application, and are not intended to limit the present application, and any person skilled in the art, after referring to the present application, should still fall within the scope of the present application when appropriate changes may be made to the parameters or settings thereof.
The optical lens provided by the embodiment has the following optical technical indexes:
the total system length TTL of the optical lens meets the following conditions: TTL is less than or equal to 38mm;
the total focal length f of the optical lens is 8.2mm;
the field angle FOV of the optical lens is 64 °;
the optical distortion of the optical lens is-11.3%;
aperture of optical lens: FNO is less than or equal to 1.4;
optical lens image plane size:
in the present embodiment, the focal length f1 of the first lens, the total focal length f of the optical lens, and the field angle FOV of the optical lens satisfy: (f 1/f) tan (FOV) =5.61. The center radius of curvature R4 of the image side surface of the second lens and the center radius of curvature R5 of the object side surface of the third lens satisfy: (r5—r4)/(r5+r4) =1.22. The focal length f3 of the third lens and the focal length f5 of the fifth lens satisfy: f3/f5=0.608. The focal length f1 of the first lens is 22.45mm. The focal length f6 of the sixth lens is 27.96mm. Abbe number V of the first lens d1 31.31; abbe number V of the third lens d3 18.79. Refractive index N of fifth lens d5 1.64; refractive index N of seventh lens d7 1.67.
As shown in fig. 2, an MTF curve chart of the optical transfer function of the optical lens of the first embodiment at normal temperature in the visible light band is shown. The optical transfer function is a more accurate, visual and common way for evaluating the imaging quality of an optical lens, and the higher and smoother the curve is, which shows that the better the imaging quality of the system is, the better the correction of various aberrations (such as spherical aberration, coma aberration, astigmatism, field curvature, axial chromatic aberration, vertical chromatic aberration and the like) is carried out. As shown in the figure, the optical transfer function MTF curve graph of the optical lens in the normal temperature state of the visible light part is smoother and more concentrated, and the full-view field (half image height Y' =4.4 mm) MTF average value reaches more than 0.6; the optical lens provided by the embodiment can reach higher imaging requirements.
As shown in fig. 3, a field curvature diagram of the optical lens in the visible light band according to the first embodiment is shown. As can be seen from the figure, the curvature of field of the optical lens of the first embodiment is controlled within ±0.2mm. The field Qu Youchen "field curvature". When the lens is curved, the intersection point of the whole light beam does not coincide with the ideal image point, and although a clear image point can be obtained at each specific point, the whole image plane is a curved surface. T represents the meridian curvature and S represents the sagittal curvature. The field curvature curve shows the distance of the current focal plane or image plane to the paraxial focal plane as a function of the field coordinates, and the meridian field curvature data is the distance measured along the Z-axis from the currently determined focal plane to the paraxial focal plane and is measured on the meridian (YZ-plane). The sagittal field curvature data measures the distance measured in a plane perpendicular to the meridian plane, the base line in the diagram being on the optical axis, the top of the curve representing the maximum field of view (angle or height), and no units being placed on the longitudinal axis, since the curve is always normalized by the maximum radial field of view.
As shown in fig. 4, a distortion chart of the optical lens in the visible light band according to the first embodiment is shown. As can be seen from the figure, the distortion of the optical lens is well controlled to be within-15%. In general, distortion is actually a generic term for perspective distortion inherent to optical lenses, i.e., distortion due to perspective, which is very detrimental to the imaging quality of photographs, after all, for the purpose of photography, but is not exaggerated, but cannot be eliminated and can only be improved because it is an inherent characteristic of lenses (convex lens converging rays, concave lens diverging rays). As can be seen from fig. 4, the distortion of the optical lens provided in the first embodiment of the present invention is only-11.3%, so that the distortion is set to balance the focal length, the angle of view and the size of the corresponding camera target surface, and the distortion caused by the distortion can be corrected by post image processing.
Fig. 5 shows a lateral optical fan diagram of the optical lens in the visible light band. The graph shows that the curves in the transverse fan graph are concentrated, that is, the spherical aberration and dispersion of the optical lens are well controlled.
As shown in fig. 6, a point diagram of the optical lens in the visible light band of the present application is shown. As can be seen from the figure, the optical lens has smaller spot radius, is more concentrated, and has good corresponding aberration and coma aberration.
Example two
As shown in fig. 7 to 12, a second embodiment of the present application is described. Fig. 7 is a schematic structural diagram of an optical lens according to a second embodiment of the present application.
As shown in fig. 7, the optical lens includes, in order from an object side to an image side: a first lens L1, a second lens L2, a third lens L3, an aperture STOP, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an optical filter L8, and an imaging plane IMA.
In the second embodiment, the curvature radius R, the center thickness Tc, the refractive index Nd, the abbe number Vd, and the cone coefficient k of each lens of the optical lens satisfy the conditions shown in table 3:
TABLE 3 Table 3
As can be seen from the above table, the object side surface of the first lens element is convex, and the image side surface is concave; the object side surface of the second lens is a concave surface, and the image side surface is a concave surface; the object side surface of the third lens is a concave surface, and the image side surface is a convex surface; the object side surface of the fourth lens is a concave surface, and the image side surface is a convex surface; the object side surface of the fifth lens is a concave surface, and the image side surface is a convex surface; the object side surface of the sixth lens is a convex surface, and the image side surface is a convex surface; the seventh lens element has a convex object-side surface and a concave image-side surface.
In the schematic configuration of the optical lens shown in fig. 7, the mirror numbers in table 3 are the numbers of the lenses from left to right. The third lens L3 is an aspherical lens, and the sixth lens L6 is an aspherical lens.
The aspherical conic coefficient can be defined by the formula (1) in the first embodiment. The following table 4 gives the higher order coefficients A, B, C, D, E, F of the aspherical lenses that can be used in embodiment two.
TABLE 4 Table 4
It should be noted that the data listed in the foregoing table are preferred data of the present application, and are not intended to limit the present application, and any person skilled in the art, after referring to the present application, should still fall within the scope of the present application when appropriate changes may be made to the parameters or settings thereof.
The optical lens provided by the embodiment has the following optical technical indexes:
the total system length TTL of the optical lens meets the following conditions: TTL is less than or equal to 38mm;
the total focal length f of the optical lens is 8.0mm;
the field angle FOV of the optical lens is 65.2 °;
the optical distortion of the optical lens is-12.05%;
aperture of optical lens: FNO is less than or equal to 1.4;
optical lens image plane size:
in the present embodiment, the focal length f1 of the first lens, the total focal length f of the optical lens, and the field angle FOV of the optical lens satisfy: (f 1/f) tan (FOV) =5.90. The center radius of curvature R4 of the image side surface of the second lens and the center radius of curvature R5 of the object side surface of the third lens satisfy: (r5—r4)/(r5+r4) =1.20. The focal length f3 of the third lens and the focal length f5 of the fifth lens satisfy: f3/f5=0.616. The focal length f1 of the first lens is 21.85mm. The focal length f6 of the sixth lens is 27.82mm. Abbe number V of the first lens d1 18.79; abbe number V of the third lens d3 25.46. Refractive index N of fifth lens d5 1.62; refractive index N of seventh lens d7 1.67.
As shown in fig. 8, an MTF curve chart of the optical transfer function of the optical lens of the second embodiment in the normal temperature state of the visible light band is shown. As shown in the figure, the optical transfer function MTF curve graph of the optical lens in the normal temperature state of the visible light part is smoother and more concentrated, and the full-view field (half image height Y' =4.4 mm) MTF average value reaches more than 0.6; the optical lens provided by the embodiment can reach higher imaging requirements.
As shown in fig. 9, a field curvature diagram of the optical lens in the visible light band according to the second embodiment is shown. As can be seen from the figure, the curvature of field of the optical lens of the second embodiment is controlled within ±0.2mm. The field Qu Youchen "field curvature". When the lens is curved, the intersection point of the whole light beam does not coincide with the ideal image point, and although a clear image point can be obtained at each specific point, the whole image plane is a curved surface. T represents the meridian curvature and S represents the sagittal curvature. The field curvature curve shows the distance of the current focal plane or image plane to the paraxial focal plane as a function of the field coordinates, and the meridian field curvature data is the distance measured along the Z-axis from the currently determined focal plane to the paraxial focal plane and is measured on the meridian (YZ-plane). The sagittal field curvature data measures the distance measured in a plane perpendicular to the meridian plane, the base line in the diagram being on the optical axis, the top of the curve representing the maximum field of view (angle or height), and no units being placed on the longitudinal axis, since the curve is always normalized by the maximum radial field of view.
As shown in fig. 10, a distortion chart of the optical lens of the second embodiment in the visible light band is shown. As can be seen from the figure, the distortion of the optical lens is well controlled to be within-15%. In general, distortion is actually a generic term for perspective distortion inherent to optical lenses, i.e., distortion due to perspective, which is very detrimental to the imaging quality of photographs, after all, for the purpose of photography, but is not exaggerated, but cannot be eliminated and can only be improved because it is an inherent characteristic of lenses (convex lens converging rays, concave lens diverging rays). As can be seen from fig. 10, the distortion of the optical lens provided in the second embodiment of the present invention is only-12.05%, so that the distortion is set to balance the focal length, the angle of view and the size of the corresponding camera target surface, and the distortion caused by the distortion can be corrected by post image processing.
Fig. 11 is a cross-sectional view of the optical lens in the visible light band according to the present application. The graph shows that the curves in the transverse fan graph are concentrated, that is, the spherical aberration and dispersion of the optical lens are well controlled.
As shown in fig. 12, a point diagram of the optical lens of the present application in the visible light band is shown. As can be seen from the figure, the optical lens has smaller spot radius, is more concentrated, and has good corresponding aberration and coma aberration.
In summary, the first and second embodiments satisfy the relationships shown in table 5 below.
| Conditional formulas/embodiments | Example 1 | Example two |
| (f1/f)*tan(FOV) | 5.61 | 5.90 |
| (R5-R4)/(R5+R4) | 1.22 | 1.20 |
| f3/f5 | 0.608 | 0.616 |
| f1 | 22.45 | 21.85 |
| f6 | 27.96 | 27.82 |
| V d1 | 31.31 | 18.79 |
| V d3 | 18.79 | 25.46 |
| N d5 | 1.64 | 1.62 |
| N d7 | 1.67 | 1.67 |
TABLE 5
It will be apparent that the embodiments described above are merely some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.
It should be noted that the terms "first," "second," and the like in the description and claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the present application described herein may be implemented in sequences other than those illustrated or described herein.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. An optical lens is characterized in that the optical lens comprises a first lens (L1), 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 (L8) and an imaging plane (IMA) which are sequentially arranged from an object side to an image side,
wherein,,
the first lens (L1) is a meniscus lens having positive optical power;
the second lens (L2) is a meniscus lens having negative optical power;
the third lens (L3) is a meniscus lens having positive optical power;
the fourth lens (L4) is a meniscus lens having negative optical power;
the fifth lens (L5) is a meniscus lens having positive optical power;
the sixth lens (L6) is a biconvex lens having positive optical power;
the seventh lens (L7) is a meniscus lens having positive optical power.
2. The optical lens according to claim 1, further comprising an aperture STOP (STOP) disposed between the third lens (L3) and the fourth lens (L4).
3. The optical lens of claim 1, wherein a focal length f1 of the first lens, a total focal length f of the optical lens, and a field angle FOV of the optical lens satisfy: 5.5.ltoreq.f 1/f. Tan (FOV) 6.0.
4. The optical lens according to claim 1, wherein the first lens (L1), the third lens (L3), the fourth lens (L4), the fifth lens (L5) and the seventh lens (L7) are all glass spherical lenses, and the second lens (L2) and the sixth lens (L6) are glass spherical lenses or glass aspherical lenses.
5. The optical lens of claim 1, wherein,
the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; and/or
The object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface.
6. The optical lens of any one of claims 1-5, wherein a center radius of curvature R4 of an image side of the second lens and a center radius of curvature R5 of an object side of the third lens satisfy: (R5-R4)/(R5+R4) is less than or equal to 1.3.
7. The optical lens according to any one of claims 1 to 5, wherein a focal length f3 of the third lens and a focal length f5 of the fifth lens satisfy: f3/f5 is less than or equal to 0.63.
8. The optical lens of claim 1, wherein,
the focal length f1 of the first lens satisfies: f1 is less than or equal to 23mm;
the focal length f6 of the sixth lens satisfies: f6 is less than or equal to 29mm.
9. The optical lens of claim 1, wherein,
abbe number V of the first lens d1 The method meets the following conditions: v (V) d1 ≤33；
Abbe number V of the third lens d3 The method meets the following conditions: v (V) d3 ≥16。
10. The optical lens of claim 1, wherein,
refractive index N of the fifth lens d5 The method meets the following conditions: n (N) d5 ≤1.67；
Refractive index N of the seventh lens d7 The method meets the following conditions: n (N) d7 ≤1.72。
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105278075A (en) * | 2014-06-13 | 2016-01-27 | 株式会社理光 | Optical imaging system, camera, and in-vehicle camera |
| CN105372789A (en) * | 2015-11-11 | 2016-03-02 | 苏州莱能士光电科技有限公司 | Distortionless high-resolution large-viewing angle unmanned aerial vehicle lens optical system |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105278075A (en) * | 2014-06-13 | 2016-01-27 | 株式会社理光 | Optical imaging system, camera, and in-vehicle camera |
| CN105372789A (en) * | 2015-11-11 | 2016-03-02 | 苏州莱能士光电科技有限公司 | Distortionless high-resolution large-viewing angle unmanned aerial vehicle lens optical system |
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