CN115857150A

CN115857150A - Optical lens

Info

Publication number: CN115857150A
Application number: CN202211649665.6A
Authority: CN
Inventors: 鲍宇旻; 付宇帝
Original assignee: Jiangxi Lianchuang Electronic Co Ltd
Current assignee: Jiangxi Lianchuang Electronic Co Ltd
Priority date: 2022-12-21
Filing date: 2022-12-21
Publication date: 2023-03-28

Abstract

The invention provides an optical lens, which comprises six lenses, and is characterized in that the six lenses are sequentially arranged from an object side to an imaging surface along an optical axis as follows: the first lens with negative focal power has a convex object-side surface and a concave image-side surface; the second lens with negative focal power, 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; a third lens having a positive optical power; a diaphragm; a fourth lens having a negative refractive power, an image-side surface of which is concave; a fifth lens element with positive refractive power having a convex object-side surface and a concave image-side surface; a sixth lens element with positive refractive power having a convex object-side surface and a concave image-side surface; the combined focal length f of the front lens at the optical lens diaphragm position _{Front side} Combined focal length f of the lens behind the diaphragm position _{Rear end} Satisfies the following conditions: f. of _{Front side} /f _{Rear end} ＜‑1.0。

Description

Optical lens

Technical Field

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

Background

With the intelligent development of automobiles, the auxiliary driving system of the automobile is gradually improved, the vehicle-mounted lens is used as one of main tools for acquiring external information by the auxiliary driving system, and the performance of the vehicle-mounted lens directly influences the performance of the auxiliary driving system.

Compared with a common optical lens, a vehicle-mounted lens in a driving auxiliary system has special requirements, for example, the vehicle-mounted camera lens requires that the caliber of the front end is as small as possible, the light transmission capability is strong, the vehicle-mounted camera lens can adapt to the change of brightness of the external environment, meanwhile, the vehicle-mounted camera lens requires higher imaging definition, the details of the external environment can be effectively distinguished, and the thermal stability is good, so that the vehicle-mounted camera lens has good resolving power at high and low temperatures so as to meet the special requirements of automatic driving.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an optical lens, which can solve one or more of the above technical problems.

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

an optical lens system comprising six lenses, in order from an object side to an image plane along an optical axis:

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

the second lens with negative focal power, 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;

a third lens having a positive optical power;

a diaphragm;

a fourth lens with negative focal power, wherein the image side surface of the fourth lens is a concave surface;

a fifth lens element with positive refractive power having a convex object-side surface and a concave image-side surface;

a sixth lens element with positive refractive power having a convex object-side surface and a concave image-side surface;

the combined focal length f of the front lens at the optical lens diaphragm position _{Front side} Combined focal length f of the lens behind the diaphragm position _{Rear end} Satisfies the following conditions: f. of _{Front side} /f _{Rear end} ＜-1.0。

Preferably, 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 less than 3.0.

Preferably, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field angle satisfy: IH/f is more than 2.0 and less than 2.3.

Preferably, the entrance pupil diameter EPD of the optical lens and the real image height IH corresponding to the maximum field angle satisfy: IH/EPD is more than 3.8 and less than 4.0.

Preferably, the incident angle CRA of the maximum field angle FOV and the maximum field angle chief ray of the optical lens on the image plane satisfies: 2.5 < (FOV/2)/CRA < 3.8.

Preferably, the effective focal length f of the optical lens and the focal length f of the second lens are equal ₂ Satisfies the following conditions: -12.0 < f ₂ /f＜-3.0。

Preferably, the effective focal length f of the optical lens and the focal length f of the sixth lens element ₆ Satisfies the following conditions: f is more than 3.0 ₆ /f＜4.5。

Preferably, the effective focal length f of the optical lens and the object-side curvature radius R of the sixth lens element ₁₁ Radius of curvature R of image side ₁₂ Respectively satisfy: r is more than 1.5 ₁₁ /f＜1.8；2.5＜R ₁₂ /f＜15.0。

Preferably, the rise Sag of the image-side surface of the sixth lens is ₁₂ And light passing semi-aperture d ₁₂ Satisfies the following conditions: sag of 0.15 ₁₂ /d ₁₂ ＜0.30。

Preferably, the total optical length TTL of the optical lens and the total sum Σ CT of the central thicknesses of the first lens element to the sixth lens element along the optical axis satisfy: 0.50 < ∑ CT/TTL < 0.70.

Compared with the prior art, the invention has the beneficial effects that: by reasonably matching the combination of the lens shape and the focal power among the lenses, the advantages of high contrast, excellent thermal stability, low processing difficulty and the like are realized.

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 the F-Tan θ distortion of the optical lens in embodiment 1 of the present invention.

Fig. 4 is a graph showing a relative illuminance of the optical lens in embodiment 1 of the present invention.

Fig. 5 is a MTF graph of the optical lens in embodiment 1 of the present invention.

Fig. 6 is a graph showing axial aberration of the optical lens in embodiment 1 of the present invention.

Fig. 7 is a vertical axis chromatic aberration diagram of the optical lens in embodiment 1 of the present invention.

Fig. 8 is a schematic structural diagram of an optical lens system according to embodiment 2 of the present invention.

Fig. 9 is a field curvature graph of the optical lens in embodiment 2 of the present invention.

Fig. 10 is a graph showing the F-Tan θ distortion of the optical lens in embodiment 2 of the present invention.

Fig. 11 is a graph showing a relative illuminance of the optical lens in embodiment 2 of the present invention.

Fig. 12 is a MTF graph of the optical lens in embodiment 2 of the present invention.

Fig. 13 is a graph illustrating axial aberration of the optical lens in embodiment 2 of the present invention.

Fig. 14 is a vertical axis chromatic aberration diagram of the optical lens in embodiment 2 of the present invention.

Fig. 15 is a schematic structural diagram of an optical lens system according to embodiment 3 of the present invention.

Fig. 16 is a field curvature graph of the optical lens in embodiment 3 of the present invention.

Fig. 17 is a graph showing the F-Tan θ distortion of the optical lens in embodiment 3 of the present invention.

Fig. 18 is a graph showing a relative illuminance of the optical lens in embodiment 3 of the present invention.

Fig. 19 is a MTF graph of the optical lens in embodiment 3 of the present invention.

Fig. 20 is a graph showing axial aberration of the optical lens in embodiment 3 of the present invention.

Fig. 21 is a vertical axis chromatic aberration diagram of the optical lens in embodiment 3 of the present invention.

Fig. 22 is a schematic structural diagram of an optical lens system according to embodiment 4 of the present invention.

Fig. 23 is a curvature of field curve diagram of the optical lens in embodiment 4 of the present invention.

Fig. 24 is a graph showing the F-Tan θ distortion of the optical lens in embodiment 4 of the present invention.

Fig. 25 is a graph showing a relative illumination of an optical lens in embodiment 4 of the present invention.

Fig. 26 is a MTF graph of the optical lens in embodiment 4 of the present invention.

Fig. 27 is a graph showing axial aberration of the optical lens in embodiment 4 of the present invention.

Fig. 28 is a vertical axis chromatic aberration diagram of the optical lens in embodiment 4 of the present invention.

Fig. 29 is a schematic structural diagram of an optical lens system according to embodiment 5 of the present invention.

Fig. 30 is a field curvature graph of the optical lens in embodiment 5 of the present invention.

Fig. 31 is a graph showing the F-Tan θ distortion of the optical lens in embodiment 5 of the present invention.

Fig. 32 is a graph showing the relative illuminance of the optical lens in embodiment 5 of the present invention.

Fig. 33 is a MTF graph of the optical lens in embodiment 5 of the present invention.

Fig. 34 is a graph showing axial aberration of the optical lens in embodiment 5 of the present invention.

Fig. 35 is a vertical axis chromatic aberration diagram of the optical lens in embodiment 5 of the present invention.

Detailed Description

For a better understanding of the present invention, various aspects of the present invention 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 invention and does not 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 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, the use of "may" mean "one or more embodiments of the invention" when describing 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 the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

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

In some embodiments, the first lens may have a negative power, which is beneficial for reducing the inclination angle of the incident light rays, thereby realizing effective sharing of a large field of view of the object space. The object side surface of the first lens is convex, and the image side surface of the first lens is concave, so that a larger field angle range can be obtained. In addition, in practical applications, considering the outdoor installation and use environment of the vehicle-mounted application-type lens, the lens may be in severe weather such as rain, snow and the like, and the first lens is set to be in a meniscus shape with the convex surface facing the object side, so that water drops and the like can slide off favorably, and the influence on the imaging of the lens can be reduced.

In some embodiments, the second lens element may have a negative focal power, and the negative focal power of the front end of the optical lens element can be shared, so that the optical lens element is beneficial to avoiding the excessive light deflection caused by the over-concentration of the focal power of the first lens element, and the difficulty in correcting chromatic aberration of the optical lens element is reduced. 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, so that the working caliber of the second lens is reduced while the light collection capability of the marginal field of view is improved, and the miniaturization of the volume of the rear end of the optical lens is facilitated; in addition, the vertical axis chromatic aberration caused by overlarge deflection angle of marginal field of view light in the process of transmitting the light from the first lens to the second lens can be effectively avoided, and the difficulty in correcting chromatic aberration of the optical lens is reduced.

In some embodiments, the third lens element may have a positive optical power, which is beneficial for reducing the deflection angle of the light rays and making the trend of the light rays smoothly transition.

In some embodiments, the fourth lens element may have a negative focal power, which is beneficial to increase an imaging area of the optical lens and improve the imaging quality of the optical lens.

In some embodiments, the fifth lens element may have a positive focal power, which is beneficial to improving the light converging capability of the peripheral field of view, and at the same time, effectively controlling the total optical length to reduce the volume of the optical lens, thereby being beneficial to the miniaturization of the optical lens. The image side surface of the fifth lens is a convex surface, so that the trend of marginal rays is smoothly transited, and the imaging quality of the optical lens is improved.

In some embodiments, the sixth lens element may have positive optical power, which is beneficial to suppress the angle of the peripheral field of view incident on the imaging plane, so as to effectively transmit more light beams to the imaging plane, thereby improving the imaging quality of the optical lens. The object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a concave surface, so that the relative illumination of the edge view field is favorably improved, the generation of a dark corner is avoided, and the imaging quality of the optical lens is improved.

In some embodiments, a stop for limiting the light beam can be arranged between the third lens and the fourth lens, so that the generation of optical lens ghost can be reduced.

In some embodiments, the aperture value FNO of the optical lens satisfies: FNO is more than 1.70 and less than 1.90. The range is satisfied, the brightness and the definition of the imaging surface of the optical lens can be balanced, and the shooting requirement of the optical lens is satisfied.

In some embodiments, the maximum field angle FOV of the optical lens satisfies: FOV is less than or equal to 130 degrees. The wide-angle detection device meets the range, is favorable for realizing wide-angle characteristics, can acquire more scene information, and meets the requirement of large-range detection of the optical lens.

In some embodiments, the incident angle CRA of the maximum field angle chief ray of the optical lens on the image plane satisfies: 16 DEG < CRA < 26 deg. Satisfying the above range, a larger tolerance error range can be provided between the CRA of the optical lens and the CRA of the chip photosensitive element, and the adaptability of the optical lens to the image sensor is improved.

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 less than 3.0. The range is satisfied, the balance between good imaging quality and miniaturization design of the optical lens is facilitated, and the requirement on the optical lens under narrow working conditions can be satisfied.

In some embodiments, the real image height IH at which the effective focal length f of the optical lens corresponds to the maximum field angle satisfies: IH/f is more than 2.0 and less than 2.3. The wide-angle characteristic can be realized by meeting the range, so that the requirement of large-range detection is met, the large image surface characteristic can be realized, and the imaging quality of the optical system is improved.

In some embodiments, the optical back focus BFL of the optical lens and the effective focal length f satisfy: 1.0 < BFL/f. The method meets the range, is favorable for obtaining balance between good imaging quality and optical back focal length easy to assemble, and reduces the difficulty of the camera module assembly process while ensuring the imaging quality of the optical lens.

In some embodiments, the real image height IH of the optical lens corresponding to the maximum field angle and the entrance pupil diameter EPD satisfy: IH/EPD is more than 3.8 and less than 4.0. The width of the light ray bundle entering the optical lens can be increased, the brightness of the optical lens at the image plane is improved, the dark angle is avoided, and meanwhile the imaging area of the optical lens can be increased.

In some embodiments, the incident angle CRA of the maximum field angle FOV and the maximum field angle chief ray of the optical lens on the image plane satisfies: 2.5 < (FOV/2)/CRA < 3.8. The wide-field optical lens has the advantages that the wide-field optical lens can realize large field of view, incident light can enter the image sensor at a proper angle, the light sensitivity of the image sensor is improved, 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 true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.45 < (IH/2)/(f × Tan (FOV/2)) < 0.55. The distortion of the optical lens can be controlled within a reasonable range, and the optical lens is convenient to restore through a software algorithm in the later stage.

In some embodiments, the effective focal length f of the optical lens and the focal length f of the first lens are different ₁ Satisfies the following conditions: -2.5 < f ₁ And/f < -1.5. The first lens has appropriate negative focal power, and is favorable for reducing the inclination angle of incident light, so that the large field of view of an object space is effectively shared, and a larger field angle range can be obtained.

In some embodiments, the effective focal length f of the optical lens and the focal length f of the second lens are different ₂ Satisfies the following conditions: -12.0 < f ₂ F is less than-3.0. The second lens has proper negative focal power and can share the negative focal power of the front end of the optical lens, thereby being beneficial to avoiding the situation that the focal power of the first lens is too concentratedThe resulting light is too deflected.

In some embodiments, the effective focal length f of the optical lens and the focal length f of the third lens are ₃ Satisfies the following conditions: 1.5 < f ₃ The/f is less than 20.0. Satisfying above-mentioned scope, can making the third lens have appropriate positive focal power, be favorable to assembling light and reduce light deflection angle simultaneously, let the light trend smooth transition, promote optical lens's the formation of image quality.

In some embodiments, the effective focal length f of the optical lens and the focal length f of the fourth lens are different ₄ Satisfies the following conditions: -5.5 < f ₄ And/f < -1.0. The fourth lens has appropriate negative focal power, so that the imaging area of the optical lens can be increased, and the imaging quality of the optical lens can be improved.

In some embodiments, the effective focal length f of the optical lens and the focal length f of the fifth lens ₄ Satisfies the following conditions: 1.0 < f ₅ The/f is less than 1.5. The fifth lens has proper positive focal power, so that the light convergence capability of the peripheral field of view is improved, the total optical length is effectively controlled, the volume of the optical lens is reduced, and the miniaturization of the optical lens is facilitated; meanwhile, the fourth lens and the cemented lens are combined to form the cemented lens, so that chromatic aberration of the optical lens can be balanced, and 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 of the sixth lens element ₆ Satisfies the following conditions: f is more than 3.0 ₆ The/f is less than 4.5. Satisfying above-mentioned scope, can making the sixth lens have appropriate positive focal power, be favorable to suppressing the angle that marginal visual field incides to the imaging surface, transmit more light beams to the imaging surface effectively, promote optical lens's imaging quality.

In some embodiments, the combined focal length f of the lens before the stop position of the optical lens _{Front side} Combined focal length f of the lens behind the diaphragm position _{Rear end} Satisfies the following conditions: f. of _{Front side} /f _{Rear end} < -1.0. The optical lens diaphragm rear lens group can reduce the correction difficulty of various aberrations of the optical lens diaphragm rear lens group, is favorable for improving the temperature drift problem of the optical lens and improves the imaging quality of the optical lens.

In some casesIn an embodiment, the effective focal length f of the optical lens and the object-side curvature radius R of the sixth lens element ₁₁ Radius of curvature R of image side ₁₂ Respectively satisfy: r is more than 1.5 ₁₁ /f＜1.8；2.5＜R ₁₂ The/f is less than 15.0. The range is met, the astigmatism of the marginal field of view is reduced while the imaging surface of the marginal field of view of the optical lens has high enough relative illumination, and the imaging quality of the optical lens is improved.

In some embodiments, the rise Sag of the image-side surface of the sixth lens ₁₂ And light passing semi-aperture d ₁₂ Satisfies the following conditions: sag is more than 0.15 ₁₂ /d ₁₂ Is less than 0.30. The light beam of the marginal field of view can be converged, and the imaging quality of the marginal field of view is improved.

In some embodiments, the total optical length TTL of the optical lens and the sum Σ CT of the central thicknesses of the first lens element to the sixth lens element along the optical axis respectively satisfy: 0.50 < ∑ CT/TTL < 0.70. Satisfying the above range, the ratio of the lens in the optical lens can be increased, and the ratio can be increased.

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 optical axis direction, 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 a quadric coefficient, and A, B, C, D, E and F are second-order, fourth-order, sixth-order, eighth-order, tenth-order and twelfth-order curved coefficients 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 by the following examples, and any other changes, substitutions, combinations or simplifications which do not depart from the gist of the present invention should be construed as being equivalent replacements 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: a first lens L1, a second lens L2, a third lens L3, an aperture stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, an optical filter G1, and a cover glass G2.

The first lens L1 has negative focal power, and the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface;

the second lens L2 has negative focal power, and the object side surface S3 is a convex surface, and the image side surface S4 is a concave surface;

the third lens L3 has positive focal power, and both the object side surface S5 and the image side surface S6 are convex surfaces;

a diaphragm ST;

the fourth lens L4 has negative focal power, and both the object-side surface S7 and the image-side surface S8 are concave surfaces;

the fifth lens L5 has positive focal power, and both the object side surface S9 and the image side surface S10 are convex surfaces;

the sixth lens element L6 has positive refractive power, and has a convex object-side surface S11 and a concave image-side surface S12;

the optical filter G1 is provided with a plane object side surface S13 and a plane image side surface S14;

the optical filter G2, the object side surface S15 and the image side surface S16 are both planes;

the imaging surface S17 is a plane;

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

TABLE 1-1

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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

Flour mark

K

A

B

C

D

E

F

S7

1.64E+00

0.00E+00

-2.66E-03

3.62E-05

-8.57E-06

-2.29E-06

1.42E-07

S8

6.54E+01

0.00E+00

3.23E-03

1.71E-06

1.45E-05

-4.22E-06

2.62E-07

Fig. 2 shows a field curvature graph 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 ± 0.08mm, which indicates that the optical lens can correct the field curvature well.

Fig. 3 shows a F-Tan θ distortion graph of example 1, which shows the F-Tan θ distortion at different image heights on the image forming plane for light rays of different wavelengths, with the horizontal axis showing the F-Tan θ distortion (unit:%) and the vertical axis showing the half field angle (unit: °). As can be seen from the figure, the F-Tan theta distortion of the optical lens is controlled to be uniformly changed within +/-50%, which shows that the F-Tan theta distortion of the optical lens is effectively controlled and is beneficial to the later processing through a software algorithm.

Fig. 4 shows a relative illuminance graph of example 1, which represents relative illuminance values at different angles of field of view on an imaging plane, with the horizontal axis representing a half field 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 80% at the maximum half field angle, indicating that the optical lens has excellent relative illuminance.

Fig. 5 shows a Modulation Transfer Function (MTF) graph of embodiment 1, which represents the degree of modulation of lens imaging representing different spatial frequencies for each field of view, with the horizontal axis representing the spatial frequency (unit: lp/mm) and the vertical axis representing the MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.3 in the whole field of view, and in the range of 0-120 lp/mm, the MTF curve is uniformly and smoothly reduced in the process from the center to the edge field of view, and the image quality and the detail resolution capability are better under the conditions of low frequency and high frequency.

Fig. 6 shows an axial aberration graph 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: μm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ± 25 μm, which indicates that the optical lens can correct the axial aberration well.

Fig. 7 is a vertical axis chromatic aberration graph 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 (0.55 μm), and 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 +/-3 mu m, which shows that the optical lens can excellently correct the chromatic aberration of the marginal field of view and the secondary spectrum of the whole image surface.

Example 2

Referring to fig. 8, 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: a first lens L1, a second lens L2, a third lens L3, an aperture stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, an optical filter G1, and a cover glass G2.

a diaphragm ST;

the fourth lens L4 has negative focal power, and the object-side surface S7 is a convex surface and the image-side surface S8 is a concave surface;

the object side surface S15 and the image side surface S16 of the optical filter G2 are both planes;

the imaging surface S17 is a plane;

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

Flour mark

K

A

B

C

D

E

F

S7

-1.43E+00

0.00E+00

1.17E-03

4.46E-05

-1.50E-06

1.06E-07

1.55E-09

S8

9.36E+01

0.00E+00

2.34E-03

-2.01E-04

5.16E-05

-5.14E-06

2.25E-07

Fig. 9 shows a field curvature graph 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 +/-0.08 mm, which shows that the optical lens can well correct the field curvature.

Fig. 10 shows a F-Tan θ distortion graph of example 2, which shows the F-Tan θ distortion at different image heights on the image forming plane for light rays of different wavelengths, with the horizontal axis showing the F-Tan θ distortion (unit:%) and the vertical axis showing the half field angle (unit: °). As can be seen from the figure, the F-Tan theta distortion of the optical lens is controlled to be uniformly changed within +/-50%, which shows that the F-Tan theta distortion of the optical lens is effectively controlled and is beneficial to the later processing through a software algorithm.

Fig. 11 shows a relative illuminance graph of example 2, which represents relative illuminance values at different angles of field of view on an imaging plane, with the horizontal axis representing a half field angle (unit: °) and the vertical axis representing relative illuminance (unit:%). As can be seen from the figure, the relative luminance value of the optical lens is still greater than 80% at the maximum half field angle, indicating that the optical lens has excellent relative luminance.

Fig. 12 shows a Modulation Transfer Function (MTF) graph of embodiment 2, which represents the degree of modulation of lens imaging representing different spatial frequencies for each field of view, with the horizontal axis representing the spatial frequency (unit: lp/mm) and the vertical axis representing the MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.3 in the whole field of view, and in the range of 0-120 lp/mm, the MTF curve is uniformly and smoothly reduced in the process from the center to the edge field of view, and the image quality and the detail resolution capability are better under the conditions of low frequency and high frequency.

Fig. 13 shows an axial aberration graph 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: μm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ± 25 μm, which indicates that the optical lens can correct the axial aberration well.

Fig. 14 is a vertical axis chromatic aberration graph 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 (0.55 μm), and 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 +/-4 mu m, which shows that the optical lens can excellently correct the 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 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: a first lens L1, a second lens L2, a third lens L3, an aperture stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, an optical filter G1, and a cover glass G2.

the third lens L3 has positive focal power, and the object side surface S5 is a concave surface, and the image side surface S6 is a convex surface;

a diaphragm ST;

the imaging surface S17 is a plane;

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

Flour mark

K

A

B

C

D

E

F

S7

-7.40E+00

0.00E+00

5.25E-03

-4.31E-04

4.04E-05

-2.40E-06

6.66E-08

S8

5.85E+00

0.00E+00

1.68E-03

-1.69E-04

2.15E-05

-1.79E-06

-1.35E-08

Fig. 16 shows a field curvature graph 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 ± 0.08mm, which indicates that the optical lens can correct the field curvature well.

Fig. 17 shows a F-Tan θ distortion graph of example 3, which shows the F-Tan θ distortion at different image heights on the image forming plane for light rays of different wavelengths, with the horizontal axis showing the F-Tan θ distortion (unit:%) and the vertical axis showing the half field angle (unit: °). As can be seen from the figure, the F-Tan theta distortion of the optical lens is controlled to be uniformly changed within +/-50%, which shows that the F-Tan theta distortion of the optical lens is effectively controlled and is beneficial to the later processing through a software algorithm.

Fig. 18 shows a relative illuminance graph of example 3, which represents relative illuminance values at different angles of field of view on the imaging plane, with the horizontal axis representing the half field angle (unit: °) and the vertical axis representing the 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 70%, indicating that the optical lens has good relative illuminance.

Fig. 19 shows a Modulation Transfer Function (MTF) graph of example 3, which represents the degree of modulation of lens imaging representing different spatial frequencies for each field of view, with the horizontal axis representing the spatial frequency (unit: lp/mm) and the vertical axis representing the MTF value. It can be seen from the figure that the MTF values of the present embodiment are both above 0.3 in the full field of view, and in the range of 0 to 120lp/mm, the MTF curves decrease uniformly and smoothly in the process from the center to the edge field of view, and have better imaging quality and better detail resolution capability in both low frequency and high frequency.

Fig. 20 shows an axial aberration graph 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: μm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ± 30 μm, which indicates that the optical lens can correct the axial aberration well.

Fig. 21 is a vertical axis chromatic aberration graph 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 (0.55 μm), and in which 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 excellently correct the 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 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: a first lens L1, a second lens L2, a third lens L3, an aperture stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, an optical filter G1, and a cover glass G2.

the second lens L2 has negative focal power, and the object side surface S3 is a convex surface, and the image side surface S4 is a concave surface; the third lens L3 has positive focal power, and the object side surface S5 is a convex surface, and the image side surface S6 is a concave surface; a diaphragm ST;

the fourth lens L4 has negative focal power, and both the object side surface S7 and the image side surface S8 are concave;

the sixth lens element L6 has positive refractive power, and has a convex object-side surface S11 and a concave image-side surface S12; the optical filter G1 is provided with a plane object side surface S13 and a plane image side surface S14;

the imaging surface S17 is a plane;

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

TABLE 4-1

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

TABLE 4-2

Flour mark

K

A

B

C

D

E

F

S7

-1.79E+00

0.00E+00

1.34E-03

8.19E-06

5.51E-07

-1.54E-08

8.96E-10

S8

5.62E+01

0.00E+00

2.52E-03

-1.47E-04

4.87E-05

-5.00E-06

2.40E-07

Fig. 23 shows a field curvature graph 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 ± 0.08mm, which indicates that the optical lens can correct the field curvature well.

Fig. 24 is a graph showing the F-Tan θ distortion of example 4, in which the F-Tan θ distortion at different image heights on the image forming plane is shown for light rays of different wavelengths, the abscissa shows the F-Tan θ distortion (unit:%), and the ordinate shows the half field angle (unit:%). As can be seen from the figure, the F-Tan theta distortion of the optical lens is controlled to be uniformly changed within +/-50%, which shows that the F-Tan theta distortion of the optical lens is effectively controlled and is beneficial to the later processing through a software algorithm.

Fig. 25 shows a relative illuminance graph of example 4, which represents relative illuminance values at different angles of field of view on the imaging plane, with the horizontal axis representing the half field angle (unit: °) and the vertical axis representing the relative illuminance (unit:%). As can be seen from the figure, the relative illuminance value of the optical lens is still greater than 80% at the maximum half field angle, indicating that the optical lens has excellent relative illuminance.

Fig. 26 shows a Modulation Transfer Function (MTF) graph of example 4, which represents the degree of modulation of lens imaging representing different spatial frequencies for each field of view, with the horizontal axis representing the spatial frequency (unit: lp/mm) and the vertical axis representing the MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.3 in the whole field of view, and in the range of 0-120 lp/mm, the MTF curve is uniformly and smoothly reduced in the process from the center to the edge field of view, and the image quality and the detail resolution capability are better under the conditions of low frequency and high frequency.

Fig. 27 shows an axial aberration graph 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: μm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ± 30 μm, which indicates that the optical lens can correct the axial aberration well.

Fig. 28 is a graph showing the vertical axis chromatic aberration of example 4, in which the chromatic aberration at different image heights on the image forming plane is shown for each wavelength with respect to the center wavelength (0.55 μm), the horizontal axis shows the vertical axis chromatic aberration value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis shows the 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 +/-3 mu m, which shows that the optical lens can excellently correct the chromatic aberration of the marginal field of view and the secondary spectrum of the whole image surface.

Example 5

Referring to fig. 29, a schematic structural view of an optical lens system according to embodiment 5 of the present invention is shown, the optical lens system sequentially includes, from an object side to an image plane along an optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, an optical filter G1, and a cover glass G2.

the third lens L3 has positive focal power, and the object side surface S5 is a convex surface, and the image side surface S6 is a concave surface;

a diaphragm ST;

the imaging surface S17 is a plane;

the relevant parameters of each lens in the optical lens in example 5 are shown in table 5-1.

TABLE 5-1

The surface shape parameters of the aspherical lens of the optical lens in example 5 are shown in table 5-2.

TABLE 5-2

Flour mark

K

A

B

C

D

E

F

S7

-2.33E+00

0.00E+00

1.70E-03

1.23E-05

-5.55E-07

1.03E-07

-1.23E-09

S8

1.48E+01

0.00E+00

2.37E-03

-1.66E-04

5.39E-05

-6.80E-06

3.67E-07

Fig. 30 shows a field curvature graph of example 5, 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 ± 0.08mm, which indicates that the optical lens can correct the field curvature well.

Fig. 31 is a graph showing the F-Tan θ distortion of example 5 at different image heights on the image forming plane for light rays of different wavelengths, in which the horizontal axis shows the F-Tan θ distortion (unit:%) and the vertical axis shows the half field angle (unit:%). As can be seen from the figure, the F-Tan theta distortion of the optical lens is controlled to be uniformly changed within +/-50%, which shows that the F-Tan theta distortion of the optical lens is effectively controlled and is beneficial to the later processing through a software algorithm.

Fig. 32 shows a relative illuminance graph of example 5, which represents relative illuminance values at different angles of field of view on the imaging plane, with the horizontal axis representing the half field angle (unit: °), and the vertical axis representing the 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 70%, indicating that the optical lens has good relative illuminance.

Fig. 33 shows a Modulation Transfer Function (MTF) graph of example 5, which represents the lens imaging modulation degree representing different spatial frequencies for each field of view, with the horizontal axis representing the spatial frequency (unit: lp/mm) and the vertical axis representing the MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.3 in the whole field of view, and in the range of 0-120 lp/mm, the MTF curve is uniformly and smoothly reduced in the process from the center to the edge field of view, and the image quality and the detail resolution capability are better under the conditions of low frequency and high frequency.

Fig. 34 shows an axial aberration graph of example 5, 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: μm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ± 30 μm, which indicates that the optical lens can correct the axial aberration well.

Fig. 35 is a graph showing the vertical axis chromatic aberration of example 5, in which the chromatic aberration at different image heights on the image formation plane is shown for each wavelength with respect to the center wavelength (0.55 μm), the horizontal axis shows the vertical axis chromatic aberration value (unit: μm) for each wavelength with respect to the center wavelength, and the vertical axis shows the 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 excellently correct the chromatic aberration of the marginal field of view and the secondary spectrum of the whole image surface.

Please refer to table 6, 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, the field angle FOV, and the values corresponding to each conditional expression in the embodiments.

TABLE 6

In summary, the optical lens of the embodiment of the invention realizes the advantages of high contrast, excellent thermal stability, low processing difficulty and the like by reasonably matching the combination of the lens shape and the focal power among the lenses.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean 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 invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. 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 above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

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

a third lens having a positive optical power;

a diaphragm;

a fourth lens having a negative refractive power, an image-side surface of which is concave;

the combined focal length f of the front lens at the optical lens diaphragm position _{Front side} Combined focal length f of the lens behind the diaphragm position _{Rear end} Satisfies the following conditions: f. of _{Front part} /f _{Rear end} ＜-1.0。

2. The optical lens of claim 1, wherein a total optical length TTL of the optical lens and a real image height IH corresponding to a maximum field angle satisfy: TTL/IH is less than 3.0.

3. The optical lens according to claim 1, wherein a real image height IH of the optical lens corresponding to an effective focal length f and a maximum field angle satisfies: IH/f is more than 2.0 and less than 2.3.

4. The optical lens of claim 1, wherein an entrance pupil diameter EPD of the optical lens satisfies a real image height IH corresponding to a maximum field angle: IH/EPD is more than 3.8 and less than 4.0.

5. The optical lens according to claim 1, wherein an incident angle CRA of a maximum field angle FOV and a maximum field angle chief ray of the optical lens on an image plane satisfies: 2.5 < (FOV/2)/CRA < 3.8.

6. An optical lens according to claim 1, characterized in that the effective focal length f of the optical lens and the focal length f of the second lens are ₂ Satisfies the following conditions: -12.0 < f ₂ /f＜-3.0。

7. An optical lens according to claim 1, characterized in that the effective focal length f of the optical lens and the focal length f of the sixth lens ₆ Satisfies the following conditions: f is more than 3.0 ₆ /f＜4.5。

8. An optical lens according to claim 1, characterized in that the effective focal length f of the optical lens and the object side radius of curvature R of the sixth lens element ₁₁ Radius of curvature R of image side ₁₂ Respectively satisfy: r is more than 1.5 ₁₁ /f＜1.8；2.5＜R ₁₂ /f＜15.0。

9. The optical lens of claim 1 wherein the sagd of the sixth lens image side surface ₁₂ And light passing semi-aperture d ₁₂ Satisfies the following conditions: sag is more than 0.15 ₁₂ /d ₁₂ ＜0.30。

10. An optical lens barrel according to claim 1, wherein a total optical length TTL of the optical lens barrel and a sum Σ CT of central thicknesses of the first lens to the sixth lens along the optical axis, respectively, satisfy: 0.50 < ∑ CT/TTL < 0.70.