CN114355583B

CN114355583B - Optical lens

Info

Publication number: CN114355583B
Application number: CN202210275174.3A
Authority: CN
Inventors: 王义龙; 曾昊杰; 李亮
Original assignee: Jiangxi Lianyi Optics Co Ltd
Current assignee: Jiangxi Lianyi Optics Co Ltd
Priority date: 2022-03-21
Filing date: 2022-03-21
Publication date: 2022-08-12
Anticipated expiration: 2042-03-21
Also published as: CN114355583A

Abstract

The invention provides an optical lens, which comprises six lenses in total, and sequentially comprises the following components from an object side to an imaging surface along an optical axis: the first lens with negative focal power has a convex object-side surface and a concave image-side surface; a second lens having a positive refractive power, both the object-side surface and the image-side surface of the second lens being convex; a third lens having a positive refractive power, both the object-side surface and the image-side surface of the third lens being convex; a fourth lens element having a negative refractive power, both the object-side surface and the image-side surface of which are concave surfaces; a fifth lens having a positive refractive power, an object-side surface of which is convex; a sixth lens element having a negative refractive power, wherein both the object-side surface and the image-side surface are concave; the total optical length TTL and the maximum field angle FOV of the optical lens meet the following requirements: 1.3mm < TTL/tan (FOV/2) < 1.6 mm. The optical lens realizes the effects of large field angle, light weight, thinness and high imaging quality.

Description

Optical lens

Technical Field

The invention relates to the technical field of imaging lenses, in particular to an optical lens.

Background

In recent years, with the rapid development of miniaturized camera lenses, the application fields thereof are also expanding, and the demands of people on the lenses are also diversified increasingly. With the reduction of the pixel size of the photosensitive element and the development of the portable electronic product toward lightness and thinness, the small wide-angle camera lens with high imaging quality gradually becomes the mainstream in the market.

However, the conventional wide-angle lens cannot simultaneously achieve both lightness and thinness and high imaging quality, and cannot meet the requirements of some users who need to achieve both lightness and thinness and high imaging quality.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an optical lens having advantages of large field angle, light weight, and high imaging quality.

In order to realize the purpose, the technical scheme of the invention is as follows:

the invention provides an optical lens, which comprises six lenses in total, and sequentially comprises the following components from an object side to an imaging surface along an optical axis:

the first lens with negative focal power has a convex object-side surface and a concave image-side surface;

a diaphragm;

a second lens having a positive refractive power, both the object-side surface and the image-side surface of the second lens being convex;

a third lens having a positive refractive power, both the object-side surface and the image-side surface of the third lens being convex;

a fourth lens element having a negative optical power, wherein both the object-side surface and the image-side surface of the fourth lens element are concave;

a fifth lens having a positive refractive power, an object-side surface of which is convex;

a sixth lens element having a negative refractive power, wherein both the object-side surface and the image-side surface are concave;

the total optical length TTL and the maximum field angle FOV of the optical lens meet the following requirements: 1.3mm < TTL/tan (FOV/2) < 1.6 mm;

compared with the prior art, the invention has the beneficial effects that: the optical lens disclosed by the application realizes the effects of large field angle, light weight, thinness and high imaging quality by reasonably matching the lens shapes and focal power combinations among the lenses.

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

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of an optical lens system according to embodiment 1 of the present invention;

fig. 2 is a field curvature graph of the optical lens in embodiment 1 of the present invention;

FIG. 3 is a graph showing F-Tan (theta) distortion curves of an optical lens in embodiment 1 of the present invention;

fig. 4 is a graph showing axial aberration of the optical lens in embodiment 1 of the present invention;

FIG. 5 is a vertical axis chromatic aberration diagram of an optical lens in embodiment 1 of the present invention;

fig. 6 is a schematic structural diagram of an optical lens system according to embodiment 2 of the present invention;

FIG. 7 is a graph of curvature of field of an optical lens in embodiment 2 of the present invention;

FIG. 8 is a graph showing F-Tan (theta) distortion curves of an optical lens in embodiment 2 of the present invention;

FIG. 9 is a graph showing axial aberrations of an optical lens system according to embodiment 2 of the present invention;

fig. 10 is a vertical axis chromatic aberration curve diagram of the optical lens in embodiment 2 of the present invention;

fig. 11 is a schematic structural diagram of an optical lens system according to embodiment 3 of the present invention;

FIG. 12 is a graph showing curvature of field of an optical lens in embodiment 3 of the present invention;

FIG. 13 is a graph showing F-Tan (theta) distortion curves of an optical lens in embodiment 3 of the present invention;

FIG. 14 is a graph showing axial aberrations of an optical lens according to embodiment 3 of the present invention;

FIG. 15 is a vertical axis chromatic aberration diagram of an optical lens in embodiment 3 of the present invention;

fig. 16 is a schematic structural diagram of an optical lens system according to embodiment 4 of the present invention;

FIG. 17 is a graph of curvature of field of an optical lens in embodiment 4 of the present invention;

FIG. 18 is a graph showing F-Tan (theta) distortion curves of an optical lens in embodiment 4 of the present invention;

FIG. 19 is a graph showing axial aberrations of an optical lens system according to embodiment 4 of the present invention;

fig. 20 is a vertical axis chromatic aberration diagram of the optical lens in embodiment 4 of the present invention.

The following detailed description will further illustrate the invention in conjunction with the above-described figures.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of embodiments of the application and does not limit the scope of the application 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 this specification, the expressions first, second, third, etc. are used only to distinguish one feature from another, and do not represent any limitation on the features. Thus, the first lens discussed below may also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

In the drawings, the thickness, size, and shape of the lens have been slightly exaggerated for convenience of explanation. In particular, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and 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; 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 called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" 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. Moreover, when a statement such as "at least one of" appears after a list of listed features, the entirety of the listed features is modified rather than modifying individual elements in the list. Furthermore, when describing embodiments of the present application, the use of "may" mean "one or more embodiments of the present application. 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 application 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 the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

An optical lens according to an embodiment of the present application includes, in order from an object side to an image side: the lens comprises a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens.

In some embodiments, the first lens has a negative optical power and the first lens has a convex-concave type. The first lens adopts the focal power and the surface type arrangement, which is beneficial to collecting the light rays with a large visual field as much as possible to enter the rear optical lens. The first lens is provided with an aspheric mirror surface, so that the central area of the optical lens has high-angle resolution, and the improvement of image resolution is facilitated. The first lens can be made of a material with a high refractive index, so that the front end aperture of the optical lens can be reduced, and the volume of the optical lens can be reduced.

In some embodiments, the second lens has a positive optical power and the second lens has a double convex surface type. The second lens adopts the focal power setting, so that the aberration generated by the first lens can be corrected, and the imaging quality of the optical lens is improved. The second lens is arranged in the shape of the face, so that the aperture of the front end of the optical lens is favorably reduced, the volume of the optical lens is reduced, the miniaturization of the optical lens is realized, the light rays which are emitted after passing through the first lens are favorably collected, and the trend of the light rays at the edge of the optical lens is in stable transition.

In some embodiments, the third lens has a positive optical power and the third lens has a double convex surface type. The third lens adopts the focal power setting, so that the aberration generated by the front lens can be corrected, and the imaging quality of the optical lens is improved. The third lens is arranged in a surface shape, so that light rays can be gathered, and the trend of the light rays at the edge of the optical lens is in stable transition.

In some embodiments, the fourth lens has a negative power and the fourth lens has a biconcave type. The fourth lens adopts the focal power setting, which is beneficial to increasing the imaging area of the optical lens and improving the imaging quality of the optical lens. The fourth lens is arranged in the surface shape, so that the monochromatic aberration generated by the fourth lens is corrected, and the imaging quality of the optical lens is improved.

In some embodiments, the fifth lens has a positive optical power and the fifth lens has a convex-concave or a biconvex shape. The fifth lens adopts the focal power setting, which is beneficial to correcting astigmatism and curvature of field generated by the front lens and improving the imaging quality of the optical lens. The fifth lens adopts the surface type arrangement, which is beneficial to converging light rays and enables the light ray trend at the edge of the optical lens to tend to be gentle, thereby effectively transmitting more light beams to the imaging surface of the optical lens and improving the imaging quality of the optical lens.

In some embodiments, the sixth lens has a negative optical power. The sixth lens has a biconcave type. The sixth lens adopts the focal power setting, which is beneficial to correcting astigmatism and curvature of field generated by the front lens and improving the imaging quality of the optical lens. The sixth lens element is arranged in the shape of the plane, so that light rays can enter an imaging plane as much as possible, the relative illumination of the optical lens can be increased, and the imaging quality of the optical lens is improved. The sixth lens can be provided with an aspheric mirror surface, so that the capability of the optical lens for correcting the peripheral field aberration can be improved, and the imaging quality of the optical lens can be improved.

In some embodiments, a stop for limiting the light beam may be disposed between the first lens and the second lens, which is beneficial to converging the light entering the optical system and reducing the aperture of the front end of the optical lens.

In some embodiments, the total optical length TTL and the maximum field angle FOV of the optical lens satisfy: 1.3mm < TTL/tan (FOV/2) < 1.6 mm. The range is met, and the requirements of the optical lens on lightness and thinness can be met on the basis of large field angle of the optical lens.

In some embodiments, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle satisfy: TTL/IH is more than 0.9 and less than 1.1. Satisfying the above range is advantageous for miniaturization of the optical lens, and makes the total length thereof compressed and the image plane enlarged balanced.

The real image height IH corresponding to the maximum field angle of the optical lens meets the effective focal length f and the field angle FOV:

the optical lens meets the range, is favorable for reducing the distortion of the optical lens, has a larger field angle and better imaging quality.

In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.0 < f1/f < -1.0. Satisfying the above range, the first lens can be made to have an appropriate negative refractive power, which is advantageous for reducing aberrations of the optical lens while increasing the angle of view of the optical lens.

In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2/f is more than 0 and less than 1.0. Satisfying the above range, the second lens can have a proper positive focal power, which is beneficial to collecting light as much as possible, so that more light enters the rear lens, and the illumination intensity of the imaging edge area is improved.

In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: f3/f is more than 0 and less than 1.2. Satisfying the above range, the third lens can have a proper positive focal power, which is beneficial to collecting light as much as possible, so that more light enters the rear lens, and the illumination intensity of the imaging edge area is improved.

In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -2.0 < f4/f < -1.0. Satisfying the above range, the fourth lens can have a suitable negative focal power, which is beneficial to reducing aberration caused by the light emitted after passing through the fourth lens.

In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2.5 < f5/f < 4.5. Satisfying the above range, the fifth lens can have a proper positive focal power, which is beneficial to correcting the aberration generated by the peripheral field of view of the front lens, and avoiding the excessive divergence of the rear light.

In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.0 < f6/f < -1.0. The sixth lens has appropriate positive focal power, so that the eccentric sensitivity of beam imaging is reduced, the aberration of the optical lens is corrected, and the imaging quality of the optical lens is improved.

In some embodiments, the object side radius of curvature R1 of the first lens and the effective focal length f of the optical lens satisfy: r1/f is more than 0.5 and less than 0.8. The wide-angle optical lens meets the range, can realize the large wide angle and the smaller effective focal length of the optical lens, and meets the requirements of the optical lens on lightness and thinness.

In some embodiments, the object side radius of curvature R10 of the fifth lens and the effective focal length f of the optical lens satisfy: r10/f is more than 1.2 and less than 2.2. The optical lens system can correct the on-axis aberration of the optical lens and is beneficial to improving the imaging quality of the optical lens.

In some embodiments, the first lens has an object-side radius of curvature R1 and an image-side radius of curvature R2 that satisfy: 2.5 < (R1+ R2)/(R1-R2) < 3.5. Satisfy above-mentioned scope, can reduce spherical aberration and coma that first lens produced, be favorable to promoting optical lens imaging quality.

In some embodiments, the fifth lens has an object-side radius of curvature R10 and an image-side radius of curvature R11 that satisfy: -1.5 < (R10+ R11)/(R10-R11) < -0.5. The astigmatism of the optical lens can be corrected, and the imaging quality of the optical lens can be improved.

In some embodiments, the central thickness CT1 of the first lens and the effective focal length f of the optical lens satisfy: CT1/f is more than 0.15 and less than 0.30. Satisfy above-mentioned scope, can realize correcting the purpose of field curvature through thicker first lens, be favorable to promoting optical lens imaging quality.

In some embodiments, the central thickness CT5 of the fifth lens and the effective focal length f of the optical lens satisfy: CT5/f is more than 0.15 and less than 0.30. The ultra-thin optical lens meets the range and is beneficial to realizing ultra-thin of the optical lens.

In some embodiments, the central thickness CT5 of the fifth lens and the sagittal height SAG10 at the object side effective aperture and the sagittal height SAG11 at the image side effective aperture satisfy: i SAG10/CT 5I < 0.2, and I SAG11/CT 5I < 0.9. The manufacturing difficulty of the lens is increased due to the fact that the thickness of the fifth lens is too large or the surface of the fifth lens is too curved is avoided, so that the production cost is reduced, and meanwhile the generation of edge aberration can be reduced.

In some embodiments, the central thickness CT6 of the sixth lens meets with sagittal height SAG12 at the object side effective aperture, sagittal height SAG13 at the image side effective aperture: i SAG12/CT6 < 2.2, | SAG13/CT6 < 0.9. The problem that the manufacturing difficulty of the lens is increased due to the fact that the thickness of the sixth lens is too large or the image side surface is too bent is avoided, so that production cost is reduced, and meanwhile the generation of edge aberration can be reduced.

In some embodiments, the sum Σ CT of all lens center thicknesses of the optical lens and the total optical length TTL satisfy: and more than or equal to 0.59 sigma CT/TTL. The optical lens can shorten the total length of the optical lens and is beneficial to the lightening and thinning of the optical lens.

In order to make the system have better optical performance, a plurality of aspheric lenses are adopted in the lens, and the surface shapes of the aspheric surfaces of the optical lens satisfy the following equation:

；

wherein z is the distance between the curved surface and the vertex of the curved surface in the direction of the optical axis, h is the distance between the optical axis and the curved surface, c is the curvature of the vertex of the curved surface, K is the coefficient of the quadric surface, and A, B, C, D, E, F, G, H are the coefficients of the second, fourth, sixth, eighth, tenth, twelfth, fourteenth and sixteenth curved surfaces, respectively.

The invention is further illustrated below in the following examples. In various embodiments, the thickness, the curvature radius, and the material selection of each lens in the optical lens are different, and the specific differences can be referred to in the parameter tables of the various embodiments. The following examples are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following examples, and any other changes, substitutions, combinations or simplifications which do not depart from the innovative points of the present invention should be construed as being equivalent substitutions and shall be included within the scope of the present invention.

Example 1

Referring to fig. 1, a schematic structural diagram of an optical lens system according to embodiment 1 of the present invention is shown, the optical lens system sequentially includes, from an object side to an image plane along an optical axis: the lens comprises a first lens L1, an aperture stop, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter G1.

The first lens element L1 has negative power, and has a convex object-side surface S1 and a concave image-side surface S2;

a diaphragm;

the second lens L2 has positive focal power, and both the object side surface S4 and the image side surface S5 are convex surfaces;

the third lens L3 has positive power, and both the object side S6 and the image side S7 are convex;

the fourth lens L4 has negative power, and both the object-side surface S8 and the image-side surface S9 are concave;

the fifth lens element L5 has positive power, and has a convex object-side surface S10 and a concave image-side surface S11;

the sixth lens L6 has a negative power and has a concave object-side surface S12 and a concave image-side surface S13.

The relevant parameters of each lens in the optical lens in example 1 are shown in table 1-1.

TABLE 1-1

The surface shape parameters of the aspherical lens of the optical lens in example 1 are shown in table 1-2.

Tables 1 to 2

In the present embodiment, a field curvature graph, an F-tan (theta) distortion graph, an axial aberration graph, and a vertical axis chromatic aberration graph of the optical lens are respectively shown in fig. 2, fig. 3, fig. 4, and fig. 5.

Fig. 2 shows a field curvature curve of example 1, which shows the degree of curvature of light rays of different wavelengths on a meridional image plane and a sagittal image plane, with the horizontal axis representing the amount of displacement (unit: mm) and the vertical axis representing the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image plane and the sagittal image plane is controlled within +/-0.07 mm, which shows that the field curvature of the optical lens is better corrected.

FIG. 3 shows F-Tan (theta) distortion curves of example 1, in which F-Tan (theta) distortion of a light ray of a center wavelength at different image heights on an image forming plane is shown, the horizontal axis shows F-Tan (theta) distortion (unit:%), and the vertical axis shows a half field angle (unit:%). As can be seen from the figure, the F-Tan (theta) distortion of the optical lens is controlled within +/-75% at the maximum half field angle, which shows that the F-Tan (theta) distortion of the optical lens is better corrected.

Fig. 4 shows an axial aberration curve of example 1, which represents the aberration on the optical axis at the imaging plane for each wavelength, with the horizontal axis representing the axial aberration value (unit: mm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ± 0.06mm, which indicates that the optical lens can effectively correct the axial aberration.

Fig. 5 shows a vertical axis chromatic aberration curve of example 1, which shows chromatic aberration at different image heights on an image forming plane for each wavelength with respect to a center wavelength (0.555 μm), the horizontal axis shows a vertical axis chromatic aberration value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis shows a normalized angle of view. As can be seen from the figure, the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within +/-6 mu m, which shows that the optical lens can effectively correct the chromatic aberration of the marginal field of view and the secondary spectrum of the whole image plane.

Example 2

Referring to fig. 6, a schematic structural diagram of an optical lens system according to embodiment 2 of the present invention is shown, the optical lens system sequentially includes, from an object side to an image plane along an optical axis: the lens comprises a first lens L1, an aperture stop, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter G1.

a diaphragm;

the third lens L3 has positive power, and both the object-side surface S6 and the image-side surface S7 are convex;

the fifth lens L5 has positive power, and both the object-side surface S10 and the image-side surface S11 are convex;

The relevant parameters of each lens in the optical lens in embodiment 2 are shown in table 2-1.

TABLE 2-1

The surface shape parameters of the aspherical lens of the optical lens in example 2 are shown in table 2-2.

Tables 2 to 2

In the present embodiment, a field curvature graph, an F-tan (theta) distortion graph, an axial aberration graph, and a vertical axis chromatic aberration graph of the optical lens are respectively shown in fig. 7, fig. 8, fig. 9, and fig. 10.

Fig. 7 shows a field curvature curve of example 2, which shows the degree of curvature of light rays of different wavelengths on a meridional image plane and a sagittal image plane, with the horizontal axis representing the amount of displacement (unit: mm) and the vertical axis representing the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image plane and the sagittal image plane is controlled within +/-0.05 mm, which indicates that the field curvature of the optical lens is better corrected.

FIG. 8 shows F-Tan (theta) distortion curves of example 2, in which F-Tan (theta) distortion of a light ray of a center wavelength at different image heights on an image forming plane is shown, the horizontal axis shows F-Tan (theta) distortion (unit:%), and the vertical axis shows a half field angle (unit:%). As can be seen from the figure, the F-Tan (theta) distortion of the optical lens is controlled within +/-75% at the maximum half field angle, which shows that the F-Tan (theta) distortion of the optical lens is better corrected.

Fig. 9 shows an axial aberration curve of example 2, which represents the aberration on the optical axis at the imaging plane for each wavelength, with the horizontal axis representing the axial aberration value (unit: mm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ± 0.03mm, which indicates that the optical lens can effectively correct the axial aberration.

Fig. 10 shows a vertical axis chromatic aberration curve of example 2, which shows chromatic aberration at different image heights on an image forming plane for each wavelength with respect to a center wavelength (0.555 μm), the horizontal axis shows a vertical axis chromatic aberration value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis shows a normalized angle of view. As can be seen from the figure, the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within +/-6 mu m, which shows that the optical lens can effectively correct the chromatic aberration of the marginal field of view and the secondary spectrum of the whole image plane.

Example 3

Referring to fig. 11, a schematic structural diagram of an optical lens system according to embodiment 3 of the present invention is shown, the optical lens system sequentially includes, from an object side to an image plane along an optical axis: the lens comprises a first lens L1, an aperture stop, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter G1.

a diaphragm;

The relevant parameters of each lens in the optical lens in example 3 are shown in table 3-1.

TABLE 3-1

The surface shape parameters of the aspherical lens of the optical lens in example 3 are shown in table 3-2.

TABLE 3-2

In the present embodiment, a field curvature graph, an F-tan (theta) distortion graph, an axial aberration graph, and a vertical axis chromatic aberration graph of the optical lens are respectively shown in fig. 12, fig. 13, fig. 14, and fig. 15.

Fig. 12 shows a field curvature curve of example 3, which shows the degree of curvature of light rays of different wavelengths on a meridional image plane and a sagittal image plane, with the horizontal axis representing the amount of displacement (unit: mm) and the vertical axis representing the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image plane and the sagittal image plane is controlled within +/-0.25 mm, which indicates that the field curvature of the optical lens is better corrected.

FIG. 13 shows F-Tan (theta) distortion curves of example 3, in which F-Tan (theta) distortion of a light ray of a center wavelength at different image heights on an image forming plane is shown, the abscissa shows F-Tan (theta) distortion (unit:%), and the ordinate shows a half field angle (unit:%). As can be seen from the figure, the F-Tan (theta) distortion of the optical lens is controlled within +/-75% at the maximum half field angle, which shows that the F-Tan (theta) distortion of the optical lens is better corrected.

Fig. 14 shows an axial aberration curve of example 3, which represents the aberration on the optical axis at the imaging plane for each wavelength, with the horizontal axis representing the axial aberration value (unit: mm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ± 0.05mm, which indicates that the optical lens can effectively correct the axial aberration.

Fig. 15 shows a vertical axis chromatic aberration curve of example 3, which shows chromatic aberration at different image heights on an image forming plane for each wavelength with respect to a center wavelength (0.555 μm), the horizontal axis shows a vertical axis chromatic aberration value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis shows a normalized angle of view. As can be seen from the figure, the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within +/-7 mu m, which shows that the optical lens can effectively correct the chromatic aberration of the marginal field of view and the secondary spectrum of the whole image plane.

Example 4

Referring to fig. 16, a schematic structural diagram of an optical lens system according to embodiment 4 of the present invention is shown, the optical lens system sequentially includes, from an object side to an image plane along an optical axis: the lens comprises a first lens L1, an aperture stop, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter G1.

a diaphragm ST;

The relevant parameters of each lens in the optical lens in example 4 are shown in table 4-1.

TABLE 4-1

The surface shape parameters of the aspherical lens of the optical lens in example 4 are shown in table 4-2.

TABLE 4-2

In the present embodiment, a field curvature graph, an F-tan (theta) distortion graph, an axial aberration graph, and a vertical axis chromatic aberration graph of the optical lens are respectively shown in fig. 17, fig. 18, fig. 19, and fig. 20.

Fig. 17 shows a field curvature curve of example 4, which shows the degree of curvature of light rays of different wavelengths on a meridional image plane and a sagittal image plane, with the horizontal axis representing the amount of displacement (unit: mm) and the vertical axis representing the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image plane and the sagittal image plane is controlled within +/-0.05 mm, which indicates that the field curvature of the optical lens is better corrected.

FIG. 18 shows F-Tan (theta) distortion curves of example 4, in which F-Tan (theta) distortion of a light ray of a center wavelength at different image heights on an image forming plane is shown, the horizontal axis shows F-Tan (theta) distortion (unit:%), and the vertical axis shows a half field angle (unit:%). As can be seen from the figure, the F-Tan (theta) distortion of the optical lens is controlled within +/-75% at the maximum half field angle, which shows that the F-Tan (theta) distortion of the optical lens is better corrected.

Fig. 19 shows an axial aberration curve of example 4, which represents the aberration on the optical axis at the imaging plane for each wavelength, with the horizontal axis representing the axial aberration value (unit: mm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ± 0.05mm, which indicates that the optical lens can effectively correct the axial aberration.

Fig. 20 shows a vertical axis chromatic aberration curve of example 4, which shows chromatic aberration at different image heights on an image forming plane for each wavelength with respect to a center wavelength (0.555 μm), the horizontal axis shows a vertical axis chromatic aberration value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis shows a normalized angle of view. As can be seen from the figure, the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within +/-5 mu m, which shows that the optical lens can effectively correct the chromatic aberration of the marginal field of view and the secondary spectrum of the whole image plane.

Please refer to table 5, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, the total optical length TTL, the f-number FNO, the real image height IH, and the field angle FOV of the optical lens, and the values corresponding to each conditional expression in the embodiments.

TABLE 5

To sum up, the optical lens of the present application realizes the effects of large field angle, light weight, thinness and high imaging quality by reasonably matching the lens shapes and focal power combinations among the lenses.

The above examples are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the invention. It should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. An optical lens system comprising six lenses, sequentially arranged from an object side to an image plane along an optical axis, comprising:

a diaphragm;

the effective focal length f of the optical lens and the curvature radius R1 of the object side surface of the first lens meet the following conditions: r1/f is more than 0.5 and less than 0.8.

2. An optical lens according to claim 1, characterized in that the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.0 < f1/f < -1.0.

3. An optical lens according to claim 1, characterized in that the effective focal length f of the optical lens and the focal length f5 of the fifth lens, the object side curvature radius R10 of the fifth lens respectively satisfy: f5/f is more than 2.5 and less than 4.5, and R10/f is more than 1.2 and less than 2.2.

4. An optical lens according to claim 1, wherein the central thickness CT1 of the first lens, the central thickness CT5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.15 < CT1/f < 0.30, 0.15 < CT5/f < 0.30.

5. An optical lens according to claim 1, characterized in that the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2/f is more than 0 and less than 1.0.

6. The optical lens of claim 1, wherein a real image height IH corresponding to a maximum field angle and a total optical length TTL of the optical lens satisfy: TTL/IH is more than 0.9 and less than 1.1.

7. The optical lens according to claim 1, wherein the real image height IH corresponding to the maximum field angle of the optical lens satisfies the effective focal length f and the field angle FOV:

。

8. the optical lens of claim 1, wherein the central thickness CT5 of the fifth lens and SAGs 10 and 11 at the object side effective aperture and SAGs 11 at the image side effective aperture respectively satisfy: i SAG10/CT 5I < 0.2 and I SAG11/CT 5I < 0.9.

9. The optical lens of claim 1, wherein the central thickness CT6 of the sixth lens meets the following criteria with sagittal height SAG12 at the object side effective aperture and sagittal height SAG13 at the image side effective aperture: i SAG12/CT6 < 2.2 and I SAG13/CT6 < 0.9.

10. An optical lens according to claim 1, wherein the sum Σ CT of all lens center thicknesses and total optical length TTL of the optical lens satisfy: and more than or equal to 0.59 sigma CT/TTL.