Optical lens

Abstract

The invention provides an optical lens, which comprises four lenses with focal power and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from an object side to an imaging surface along an optical axis, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a convex surface; the third lens has positive focal power, and the image side surface of the third lens is a convex surface; the fourth lens has positive focal power, and the object side surface of the fourth lens is a convex surface near the optical axis; wherein the optical total length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens meet the following conditions: 2.5 lt; tTL / IHlt; 3.3, 4, 5, 6, 7; the effective focal length f of the optical lens, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy 0.15 lt; f / f3 + f / f4lt; and 0.4 part. The optical lens provided by the invention can be suitable for infrared light bands, and has one or more advantages of large field angle, large image plane, high imaging quality and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and particularly to an optical lens. Background Art

[0002] The OMS (Occupancy Monitoring System) optical lens is the core component of the intelligent cockpit perception layer, mainly responsible for core functions such as driver status monitoring (DMS), passenger identity recognition, detection of children left behind, and cockpit behavior analysis. With the continuous popularization of intelligent driving and the mandatory implementation of global safety regulations for children left behind, cockpit monitoring has been upgraded from "single driver monitoring" to "multi-target perception of the entire cockpit", posing higher requirements for the performance of OMS lenses. Currently, OMS lenses mainly have problems such as poor resolution, low resolution, and easy defocus in high and low temperature environments. Generally, they can only be applied in situations with good light and cannot meet the usage requirements in environments with poor light at night. Therefore, developing an OMS optical lens that兼顾全座舱覆盖、高细节捕捉、低光清晰成像 has become an urgent need for the industry development. Summary of the Invention

[0003] In view of the above problems, the purpose of the present invention is to provide an optical lens, which has the advantage of excellent imaging quality.

[0004] The technical solution adopted by the present invention is as follows:

[0005] An optical lens, the number of lenses with optical power is four, and successively includes from the object side to the imaging surface along the optical axis:

[0006] A first lens with negative optical power, its object side is convex, and its image side is concave;

[0007] A second lens with positive optical power, its object side is convex, and its image side is convex;

[0008] A third lens with positive optical power, its image side is convex;

[0009] A fourth lens with positive optical power, its object side is convex near the optical axis;

[0010] Among them, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.5 < TTL / IH < 3.3; the effective focal length f of the optical lens, the focal length f3 of the third lens, and the focal length f4 of the fourth lens satisfy: 0.15 < f / f3 + f / f4 < 0.4.

[0011] It should be noted that the part "兼顾全座舱覆盖、高细节捕捉、低光清晰成像" in the original text seems to be an incomplete or incorrect expression. I translated it as literally as possible. If there is a more accurate or complete expression, it can be adjusted accordingly.Further preferably, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 50° < f × FOV / IH < 70°.

[0012] Further preferably, the focal length f1 of the first lens and the combined focal length f12 of the first lens and the second lens satisfy: -1.1 < f1 / f12 < -0.5; the focal length f2 of the second lens and the combined focal length f12 of the first lens and the second lens satisfy: 0.75 < f2 / f12 < 1.3.

[0013] Further preferably, the combined focal length f12 of the first lens and the second lens and the combined focal length f34 of the third lens and the fourth lens satisfy: 0.27 < f12 / f34 < 0.77.

[0014] Further preferably, the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0 / ° < TTL / IH / FOV < 0.03 / °.

[0015] Further preferably, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.9 < (R1 + R2) / (R1 - R2) < 1.3.

[0016] Further preferably, the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: -8.3 < (R7 + R8) / (R7 - R8) < 19. [[ID=1,7]]

[0017] Further preferably, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.9 < f1 / f2 < -0.6.

[0018] Further preferably, the clear aperture radius DM12 of the image side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 1.6 < 2 × DM12 / R2 < 2.

[0019] Further preferably, the Abbe number Vd3 of the third lens and the Abbe number Vd4 of the fourth lens satisfy: 30 < Vd3 - Vd4 < 36.

[0020] The optical lens provided by the present invention has four lenses with optical power. Through specific surface shape matching and reasonable optical power distribution, it can be applied to the infrared light band, can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and enable the lens to have one or more advantages such as a large field angle, a large image plane, and high imaging quality. Description of the Drawings

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0022] Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0023] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0024] Figure 3 This is an F-Theta distortion curve of the optical lens in Embodiment 1 of the present invention.

[0025] Figure 4 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 6 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0029] Figure 8 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0030] Figure 9 This is the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 10 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 11 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 12 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 15 This is the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 16 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 17 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0039] Figure 18 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 19 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0041] Figure 20 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0042] Figure 21 This is the F-Theta distortion curve of the optical lens in Embodiment 4 of the present invention.

[0043] Figure 22 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0044] Figure 23 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0045] Figure 24 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0046] Figure 25 This is a schematic diagram of the optical lens structure in Embodiment 5 of the present invention.

[0047] Figure 26 This is a field curvature curve diagram of the optical lens in Embodiment 5 of the present invention.

[0048] Figure 27 This is the F-Theta distortion curve of the optical lens in Embodiment 5 of the present invention.

[0049] Figure 28 This is an axial aberration curve of the optical lens in Embodiment 5 of the present invention.

[0050] Figure 29 This is a chromatic aberration curve of the optical lens in Embodiment 5 of the present invention.

[0051] Figure 30 This is the MTF curve of the optical lens in Embodiment 5 of the present invention.

[0052] Figure 31 This is a schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0053] Figure 32This is a field curvature curve diagram of the optical lens in Embodiment 6 of the present invention.

[0054] Figure 33 This is an F-Theta distortion curve of the optical lens in Embodiment 6 of the present invention.

[0055] Figure 34 This is an axial aberration curve of the optical lens in Embodiment 6 of the present invention.

[0056] Figure 35 This is a chromatic aberration curve of the optical lens in Embodiment 6 of the present invention.

[0057] Figure 36 This is the MTF curve of the optical lens in Embodiment 6 of the present invention.

[0058] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0059] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0060] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0061] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0062] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity 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 location of the concaveness 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 subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0063] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0064] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0065] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0066] This invention provides an optical lens with four lenses having optical power, which are arranged sequentially from the object side to the imaging plane along the optical axis as a first lens, a second lens, a third lens, and a fourth lens.

[0067] In some embodiments, the first lens may have negative optical power, its object-side surface may be convex, and its image-side surface may be concave. The second lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The third lens may have positive optical power, its object-side surface may be concave or convex, and its image-side surface may be convex. The fourth lens may have positive optical power, its object-side surface may be convex near the optical axis, and its image-side surface may be concave or convex.

[0068] In some embodiments, the optical lens may also include an aperture stop, which may be located between the second lens and the third lens. It is understood that the aperture stop is used to limit the amount of light entering the lens, thereby altering the brightness of the image.

[0069] In some embodiments, the optical lens may further include a protective glass disposed along the optical axis between the fourth lens and the imaging plane. The protective glass serves to protect the optical lens, prevent damage to the image sensor, and improve the optical lens's shock and scratch resistance, while having almost no impact on the image quality of the optical lens.

[0070] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.5 < TTL / IH < 3.3; the effective focal length f of the optical lens, the focal length f3 of the third lens, and the focal length f4 of the fourth lens satisfy: 0.15 < f / f3 + f / f4 < 0.4. Meeting the above ranges makes the total length of the optical system shorter and the lens structure more compact, thereby achieving miniaturization. At the same time, the combination of the third lens and the fourth lens is conducive to balancing the spherical aberration and chromatic aberration of the lens and shortening the back focal length to reduce the total length.

[0071] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 50° < f × FOV / IH < 70°. Meeting the above range is conducive to balancing the relationship among the focal length, field angle, and image height of the optical lens, making the optical lens have good optical performance.

[0072] In some embodiments, the focal length f1 of the first lens and the combined focal length f12 of the first lens and the second lens satisfy: -1.1 < f1 / f12 < -0.5; the focal length f2 of the second lens and the combined focal length f12 of the first lens and the second lens satisfy: 0.75 < f2 / f12 < 1.3. Meeting the above ranges helps to shorten the field curvature of the optical imaging lens system and reduce the axial spherical aberration by reasonably distributing the combined focal length of the first lens and the second lens.

[0073] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f34 of the third lens and the fourth lens satisfy: 0.27 < f12 / f34 < 0.77. Meeting the above range reasonably limits the ratio of the optical power of the lens groups before and after the aperture, which is conducive to correcting the chromatic aberration and field curvature of the optical system, reducing the light deflection angle, lowering the sensitivity, and reducing the lens forming difficulty.

[0074] In some embodiments, the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: <0 / ° < TTL / IH / FOV < 0.03 / °. Meeting the above range is conducive to balancing the relationship among the total length, image height, and field angle of the optical lens.

[0075] In some embodiments, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.9 < (R1 + R2) / (R1 - R2) < 1.3. Meeting the above range reasonably controls the surface shape of the first lens, and thus controls the shape of the first lens, making the aberration introduced by the first lens controlled within a reasonable range, thereby reducing the difficulty of correcting aberration in the subsequent optical system and improving the imaging quality.

[0076] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: -8.3 < (R7 + R8) / (R7 - R8) < 19. Satisfying the above range and reasonably controlling the surface shape of the fourth lens helps to control the light trend of the marginal field of view and improve the imaging quality of the marginal field of view.

[0077] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.9 < f1 / f2 < -0.6. Satisfying the above range enables the first lens and the second lens to form chromatic aberration compensation, which helps to compress the system length and balance the field curvature.

[0078] In some embodiments, the clear aperture semi-diameter DM12 of the image side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 1.6 < 2×DM12 / R2 < 2. Satisfying the above range can avoid the lens being super hemispherical and greatly reduce the processing difficulty of the first lens.

[0079] In some embodiments, the Abbe number Vd3 of the third lens and the Abbe number Vd4 of the fourth lens satisfy: 30 < Vd3 - Vd4 < 36. Satisfying the above range, the third lens uses a high Abbe coefficient and low infrared dispersion material, which can reduce the focus shift and correct the infrared resolution. At the same time, the third lens and the fourth lens adopt a combination of lenses with high and low Abbe coefficients, which can cancel the axial chromatic aberration and is beneficial to achieving clear imaging under infrared light.

[0080] In some embodiments, the distance BL on the optical axis from the image side surface of the fourth lens to the imaging surface and the total optical length TTL of the optical lens satisfy: 0.1 < BL / TTL < 0.2. Satisfying the above range is beneficial to achieving a short back focus of the optical lens. Moreover, when ensuring sufficient space for the installation and focusing of optical elements, it is beneficial to miniaturize the optical lens.

[0081] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6.5 < TTL / f < 9.5; the true image height IH corresponding to the maximum field angle of view of the optical lens and the effective focal length f of the optical lens satisfy: 2 < IH / f < 3.2. Satisfying the above range can effectively limit the lens length and is beneficial to miniaturizing the optical lens. At the same time, it can achieve an ultra-large field angle of view and imaging range, and can achieve the characteristics of a large image plane while ensuring the depth of field of the optical lens, thereby improving the imaging quality of the optical system.

[0082] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -0.9 < f / f1 < -0.55; the object-side curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: 7.5 < R1 / f < 1500; the image-side curvature radius R2 of the first lens and the effective focal length f of the optical lens satisfy: 0.8 < R2 / f < 1.3. Meeting the above ranges is conducive to the first lens receiving large-angle incident light, expanding the field angle range of the optical lens, reducing the sensitivity of the optical lens, and realizing the miniaturized design of the optical lens. At the same time, by reasonably setting the surface shape of the first lens, light can enter the rear optical system smoothly, thereby slowing down the trend of marginal light, which is beneficial to reducing the incident angle of the chief ray in each field of view and improving the imaging quality of the optical lens.

[0083] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.45 < f / f2 < 0.62; the object-side curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: 2 < R3 / f < 11; the image-side curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: -4.2 < R4 / f < -1.4. Meeting the above ranges, the second lens has a positive optical power and can converge the incident light at the front end, which is beneficial to correcting the aberration and distortion of the edge field of view brought by the front-end lens, making the lens have the characteristic of small distortion and providing a high-definition imaging effect. The second lens is a biconvex lens, which is conducive to gently converging and collecting the front beam, beneficial to improving the imaging quality of the optical lens, and at the same time reducing the aperture of the rear fourth lens, thereby achieving miniaturization.

[0084] In some embodiments, the object-side curvature radius R3 of the second lens and the image-side curvature radius R4 of the second lens satisfy: -0.33 < (R3 + R4) / (R3 - R4) < 0.75. Meeting the above range is conducive to the contraction of light in the wide-angle field of view, thereby adjusting the trend of the marginal beam and ensuring that the optical lens has a large field angle.

[0085] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.01 < f / f3 < 0.2; the object-side curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: -40 < R5 / f < 105; the image-side curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: -17 < R6 / f < -2.4. Meeting the above ranges, the third lens has a positive optical power and realizes aberration complementarity with the front and rear optical systems, thereby achieving high imaging quality of the optical lens. At the same time, it can adjust the trend of light, which is beneficial to reducing the aperture of the subsequent lens and thus reducing costs.

[0086] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0 < f / f4 < 0.36; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 1.3 < R7 / f < 3.4; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -7.8 < R8 / f < 15. Meeting the above ranges helps to further converge and focus the already converged light beam, which is conducive to achieving high imaging quality and reducing the difficulty of lens processing and shaping.

[0087] In some embodiments, the maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 60° < FOV / Fno < 80°. Meeting the above range is beneficial to expanding the field angle of the optical lens and increasing the aperture of the optical lens, achieving the wide-angle and large-aperture characteristics of the lens.

[0088] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 5 < IH / EPD < 7. Meeting the above range makes the field and light flux balanced and improves the imaging quality of the lens.

[0089] In some embodiments, the maximum field angle FOV of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 20° / mm < FOV / IH < 26° / mm. Meeting the above range ensures that the optical lens has a large field angle while meeting the image height requirements, thereby enabling the optical lens to have good optical performance.

[0090] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the f-number Fno of the optical lens satisfy: 2.7mm < IH / Fno < 3.3mm. Meeting the above range can improve the edge brightness of the lens image, enhance the relative illuminance of the optical system, and optimize the imaging quality.

[0091] In some embodiments, the object-side curvature radius R1 of the first lens, the image-side curvature radius R2 of the first lens, and the central thickness CT1 of the first lens satisfy: 3.6 < R1 / (R2 + CT1) < 750. Meeting the above range can reduce the processing difficulty of the lens, reduce the correction difficulty of the peripheral field distortion, and control the distortion within a reasonable range.

[0092] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: 0 < f2 / f3 < 0.4. Meeting the above range is beneficial to correcting chromatic aberration and improving the resolution of the system.

[0093] In some embodiments, the central thickness CT1 of the first lens and the central thickness CT2 of the second lens satisfy: 0.45 < CT1 / CT2 < 0.9; the central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 0.9 < CT2 / CT3 < 1.9. Meeting the above ranges can improve the stability of the lens and reduce the temperature drift.

[0094] In some embodiments, the sum ΣCT of the central thicknesses of the four lenses and the total optical length TTL of the optical lens satisfy: 0.45 < ΣCT / TTL < 0.8. Meeting the above range can effectively compress the total length of the lens, which is beneficial to the structural design and production process of the lens.

[0095] In some embodiments, the central thickness CT2 of the second lens, the central thickness CT3 of the third lens and the focal length f3 of the third lens satisfy: 0.01 < (CT2 + CT3) / f3 < 0.45. Meeting the above range, the second lens and the third lens form a thick lens group, forming a relatively high positive refractive power and承担主要会聚任务, which helps to improve the structural stability and optical performance.

[0096] In some embodiments, the sagittal height SAG12 of the image-side clear aperture semi-diameter of the first lens, the sagittal height SAG11 of the object-side clear aperture semi-diameter of the first lens and the object-side clear aperture semi-diameter DM11 of the first lens satisfy: 0.1 < (SAG12 - SAG11) / DM11 < 0.35. Meeting the above range, reasonably controlling the shape of the first lens can reduce its forming difficulty, thereby reducing the processing sensitivity and being beneficial to improving the production yield of the lens.

[0097] In some embodiments, the sagittal height SAG22 of the image-side clear aperture semi-diameter of the second lens, the sagittal height SAG11 of the object-side clear aperture semi-diameter of the first lens and the central thickness CT2 of the second lens satisfy: -0.3 < (SAG22 - SAG11) / CT2 < -0.04. Meeting the above range is beneficial to correcting the coma of the off-axis field and is beneficial to improving the imaging quality of the off-axis field of the optical lens.

[0098] In some embodiments, the sagittal height SAG41 of the object-side clear aperture semi-diameter of the fourth lens and the object-side clear aperture semi-diameter DM41 of the fourth lens satisfy: -0.1 < SAG41 / DM41 < 0.15. Meeting the above range, reasonably controlling the sagittal height and aperture of the first side of the fourth lens, controlling the light beam trend and performing the final imaging, ensuring that the opening angle of the fourth lens is within a certain range, is beneficial to the optical lens to achieve high resolution and makes the optical lens have high imaging quality.

[0099] In some embodiments, the clear aperture radius DM11 of the object side surface of the first lens and the clear aperture radius DM21 of the object side surface of the second lens satisfy: 2 < DM11 / DM21 < 3. Meeting the above range can ensure that light enters the lens within a large range, ensuring that the lens has a large field angle.

[0100] In some embodiments, the clear aperture radius DM11 of the object side surface of the first lens and the clear aperture radius DM42 of the image side surface of the fourth lens satisfy: 1.7 < DM11 / DM42 < 2.5. Meeting the above range can reasonably set the aperture relationship between the first and last lenses, ensuring that as much light as possible enters the system while increasing the area of light entering the image plane, making the lens have a high relative illumination.

[0101] In some embodiments, the clear aperture radius DM11 of the object side surface of the first lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.75 < DM11 / IH < 0.95. Meeting the above range can ensure that the lens has a large field angle while having a moderate overall size.

[0102] In some embodiments, the clear aperture radius DM11 of the object side surface of the first lens and the focal length f1 of the first lens satisfy: -2.2 < DM11 / f1 < -1.1. Meeting the above range can reasonably control the lens shape of the first lens by controlling the ratio of the clear aperture radius of the object side surface of the first lens to the focal length of the first lens, making light enter the object side surface of the first lens at the maximum incident angle, and realizing the wide-angleization of the optical system.

[0103] In some embodiments, the clear aperture radius DM42 of the image side surface of the fourth lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.32 < DM42 / IH < 0.48. Meeting the above range is beneficial for the principal ray of the edge field to smoothly exit to the imaging plane.

[0104] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half-field angle of the optical lens satisfy: 0.85 < (IH / 2) / (f×θ) < 1.15. Meeting the above range can better achieve small distortion.

[0105] In some embodiments, the optical lens satisfies the following conditional expressions: 2.1 mm < f < 3.2 mm; 140° < FOV < 170°; 18 mm < TTL < 23 mm; 2 < Fno < 2.5; 6 mm < IH < 7.5 mm; 17° < CRA < 42°. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, and CRA represents the principal ray incident angle at the maximum image height of the optical lens. Meeting the above ranges, the optical lens can be applicable to the infrared light band and has at least one or more advantages such as a large field of view angle, a large image plane, and high imaging quality.

[0106] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. Additionally, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention adopts a lens structure with a combination of four glass and plastic lenses. More specifically, the first lens and the second lens can adopt glass lenses, and the third lens and the fourth lens can adopt plastic lenses. Adopting a glass-plastic hybrid structure can improve the thermal stability, effectively reduce the cost, correct the aberration, reduce the volume, and provide an optical lens product with higher cost performance.

[0107] In some embodiments, the first lens, the second lens, the third lens, and the fourth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, in the optical lens provided by the present invention, the first lens and the second lens can adopt spherical lenses, and the third lens and the fourth lens can adopt aspherical lenses.

[0108] In various embodiments of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0109]

[0110] where z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and B, C, D, E, F, G, H are the surface coefficients of the fourth order, sixth order, eighth order, tenth order, twelfth order, fourteenth order, and sixteenth order respectively.

[0111] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0112] Example 1

[0113] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging surface, the following components in sequence: a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, and a protective glass G1.

[0114] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0115] The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is convex.

[0116] The third lens L3 has positive optical power, its object side S5 is concave, and its image side S6 is convex.

[0117] The fourth lens L4 has positive optical power, its object side S7 is convex near the optical axis, and its image side S8 is concave.

[0118] The object side S9 and image side S10 of the protective glass G1 are both flat.

[0119] The imaging plane S11 is a plane.

[0120] The first lens L1 and the second lens L2 are glass spherical lenses, while the third lens L3 and the fourth lens L4 are plastic aspherical lenses.

[0121] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0122] Table 1-1

[0123]

[0124] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0125] Table 1-2

[0126] Face number K B C D E F G H S5 1.50E+02 -5.83E-03 6.35E-04 -9.23E-04 2.70E-04 -4.34E-05 0.00E+00 0.00E+00 S6 1.50E+02 -2.70E-02 2.92E-03 -1.96E-04 -1.34E-06 6.76E-07 0.00E+00 0.00E+00 S7 -8.88E+00 4.53E-03 -4.63E-03 7.47E-04 -7.24E-05 2.83E-06 0.00E+00 0.00E+00 S8 -1.50E+02 9.64E-03 -3.60E-03 4.64E-04 -3.11E-05 9.00E-07 0.00E+00 0.00E+00

[0127] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 100 are respectively as follows: Figures 2 to 6 As shown.

[0128] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.04 mm to 0.06 mm, indicating that the optical lens 100 can effectively correct the field curvature.

[0129] Figure 3 The F-Theta distortion curve of Example 1 is shown, which represents the distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the distortion of the optical lens is controlled within 0% to 5%, indicating that the optical lens 100 can effectively correct distortion.

[0130] Figure 4 The diagram shows the axial aberration curves for Example 1, which represent the aberrations of each wavelength along the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the diagram, the axial aberration offset is controlled within ±0.02 mm, indicating that the optical lens 100 can effectively correct axial aberrations.

[0131] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.950 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -6 μm to 5 μm, indicating that the optical lens 100 can effectively correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0132] Figure 6 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.2 throughout the entire field of view. Within the range of 0–120 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0133] Example 2

[0134] Please see Figure 7 The figure shown is a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0135] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0136] Table 2-1

[0137]

[0138]

[0139] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0140] Table 2-2

[0141] Face number K B C D E F G H S5 1.07E+02 -1.08E-02 8.02E-04 -1.05E-03 2.40E-04 -4.51E-05 -1.08E-05 3.94E-06 S6 1.21E+02 -3.01E-02 2.87E-03 -2.05E-04 -1.72E-06 5.56E-07 6.62E-09 1.22E-09 S7 -9.82E+00 4.95E-03 -4.25E-03 7.59E-04 -7.42E-05 2.95E-06 3.14E-08 9.23E-10 S8 -3.18E+01 1.34E-02 -3.37E-03 4.61E-04 -3.30E-05 8.23E-07 1.58E-08 8.24E-10

[0142] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 200 are respectively as follows: Figures 8 to 12 As shown.

[0143] from Figure 8 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.04mm, indicating that the optical lens 200 can effectively correct field curvature. From Figure 9 As can be seen, the distortion of the optical lens is controlled within 0% to 5%, indicating that the optical lens 200 can effectively correct distortion. From... Figure 10 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 200 can effectively correct axial aberration. From Figure 11 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±5μm, indicating that the optical lens 200 can excellently correct chromatic aberration at the edge of the field of view and the second-order spectrum of the entire image plane. From Figure 12 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0144] Example 3

[0145] Please see Figure 13The figure shown is a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0146] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0147] Table 3-1

[0148]

[0149]

[0150] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0151] Table 3-2

[0152] Face number K B C D E F G H S5 -1.25E+02 -8.78E-03 1.38E-04 -1.08E-03 3.78E-04 1.49E-04 -1.39E-04 2.17E-05 S6 -3.92E+00 -2.48E-02 4.25E-03 -5.99E-04 1.06E-05 4.46E-06 7.42E-07 -1.75E-07 S7 -2.08E+01 3.23E-04 -3.33E-03 1.10E-03 -2.03E-04 1.44E-05 1.03E-06 -1.66E-07 S8 -6.35E+00 9.34E-03 -2.18E-03 3.07E-04 -2.21E-05 8.57E-08 1.36E-07 -9.51E-09

[0153] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 300 are respectively as follows: Figures 14 to 18 As shown.

[0154] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, indicating that the optical lens 300 can effectively correct field curvature. From Figure 15 As can be seen, the distortion of the optical lens is controlled within -15% to 0%, indicating that the optical lens 300 can effectively correct distortion. From... Figure 16 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.02mm, indicating that the optical lens 300 can effectively correct axial aberration. From Figure 17 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens 300 can excellently correct chromatic aberration at the edge of the field of view and the second-order spectrum of the entire image plane. From Figure 18 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0155] Example 4

[0156] Please see Figure 19The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S5 of the third lens L3 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0157] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0158] Table 4-1

[0159]

[0160] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0161] Table 4-2

[0162] Face number K B C D E F G H S5 1.50E+02 -4.11E-03 -2.61E-04 -4.01E-04 3.48E-04 -1.07E-04 0.00E+00 0.00E+00 S6 1.50E+02 -2.75E-02 3.22E-03 -2.28E-04 1.41E-06 7.67E-07 0.00E+00 0.00E+00 S7 -1.19E+01 4.33E-03 -5.24E-03 7.63E-04 -6.95E-05 3.29E-06 0.00E+00 0.00E+00 S8 1.61E+01 1.08E-02 -4.23E-03 5.52E-04 -3.63E-05 1.19E-06 0.00E+00 0.00E+00

[0163] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 400 are respectively as follows: Figures 20 to 24 As shown.

[0164] from Figure 20 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.08mm to 0.04mm, indicating that the optical lens 400 can effectively correct field curvature. From Figure 21 As can be seen, the distortion of the optical lens is controlled within 0% to 10%, indicating that the optical lens 400 can effectively correct distortion. From... Figure 22 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 400 can effectively correct axial aberration. From Figure 23 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±4μm, indicating that the optical lens 400 can excellently correct chromatic aberration at the edge of the field of view and the second-order spectrum of the entire image plane. From Figure 24 As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0165] Example 5

[0166] Please see Figure 25The figure shown is a schematic diagram of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S5 of the third lens L3 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0167] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0168] Table 5-1

[0169]

[0170] The surface profile parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0171] Table 5-2

[0172] Face number K B C D E F G H S5 -1.50E+02 -5.65E-03 8.19E-04 -1.21E-03 5.01E-04 -8.44E-05 0.00E+00 0.00E+00 S6 2.54E+01 -2.32E-02 1.71E-03 -5.76E-05 1.61E-06 -2.15E-07 0.00E+00 0.00E+00 S7 -3.29E+01 1.78E-03 -5.01E-03 8.33E-04 -7.06E-05 3.45E-06 0.00E+00 0.00E+00 S8 7.80E+00 1.09E-02 -4.07E-03 5.16E-04 -3.30E-05 7.46E-07 0.00E+00 0.00E+00

[0173] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 500 are respectively as follows: Figures 26 to 30 As shown.

[0174] from Figure 26 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.06mm to 0.04mm, indicating that the optical lens 500 can effectively correct field curvature. From Figure 27 As can be seen, the distortion of the optical lens is controlled within -15% to 0%, indicating that the optical lens 500 can effectively correct distortion. From... Figure 28 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.03mm, indicating that the optical lens 500 can effectively correct axial aberration. From Figure 29 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3μm to 2μm, indicating that the optical lens 500 can excellently correct chromatic aberration at the edges of the field of view and the second-order spectrum of the entire image plane. From Figure 30 As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0175] Example 6

[0176] Please see Figure 31The figure shown is a schematic diagram of the structure of the optical lens 600 provided in Embodiment 6 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side S8 of the fourth lens L4 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0177] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0178] Table 6-1

[0179]

[0180] The surface profile parameters of the aspherical lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0181] Table 6-2

[0182] Face number K B C D E F G H S5 1.50E+02 -1.43E-02 1.90E-03 -1.51E-03 3.50E-05 1.70E-05 4.78E-05 -3.66E-05 S6 1.20E+02 -3.92E-02 3.03E-03 -1.98E-04 -1.19E-05 -1.15E-06 -3.38E-07 1.56E-08 S7 -6.26E+01 -9.01E-03 -3.33E-03 8.48E-04 -8.69E-05 -1.96E-06 -6.88E-07 1.17E-07 S8 1.74E+01 1.25E-02 -1.24E-03 2.40E-04 -3.13E-05 1.11E-06 2.78E-08 1.58E-09

[0183] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 600 are respectively as follows: Figures 32 to 36 As shown.

[0184] from Figure 32 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.1mm to 0.02mm, indicating that the optical lens 600 can effectively correct field curvature. From Figure 33 As can be seen, the distortion of the optical lens is controlled within 0% to 10%, indicating that the optical lens 600 can effectively correct distortion. From... Figure 34 As can be seen, the axial aberration offset is controlled within -0.05mm to 0.02mm, indicating that the optical lens 600 can effectively correct axial aberration. From Figure 35 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±3μm, indicating that the 600 optical lens can excellently correct chromatic aberration at the edges of the field of view and the second-order spectrum of the entire image plane. From Figure 36 As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0185] Please refer to Table 7 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, principal ray incident angle CRA at the maximum image height, true image height IH corresponding to the maximum field of view, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0186] Table 7

[0187]

[0188]

[0189] In summary, the optical lens provided by the present invention has four lenses with optical power. Through specific surface shape matching and reasonable optical power distribution, it can be applied to the infrared light band, improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as a large field of view, a large image plane, and high imaging quality.

[0190] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0191] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens having four lenses with optical power, characterized in that, It sequentially includes, from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side surface is convex and whose image side surface is concave; A second lens with a positive optical power, whose object side surface is convex and whose image side surface is convex; A third lens with a positive optical power, whose image side surface is convex; A fourth lens with a positive optical power, whose object side surface is convex near the optical axis; Wherein, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.5 < TTL / IH < 3.3; the effective focal length f of the optical lens, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: 0.15 < f / f3 + f / f4 < 0.

4.

2. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens, the maximum field angle FOV of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 50° < f×FOV / IH < 70°.

3. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the combined focal length f12 of the first lens and the second lens satisfy: -1.1 < f1 / f12 < -0.5; the focal length f2 of the second lens and the combined focal length f12 of the first lens and the second lens satisfy: 0.75 < f2 / f12 < 1.

3.

4. The optical lens according to claim 1, characterized in that, The combined focal length f12 of the first lens and the second lens and the combined focal length f34 of the third lens and the fourth lens satisfy: 0.27 < f12 / f34 < 0.

77.

5. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0 / ° < TTL / IH / FOV < 0.03 / °.

6. The optical lens according to claim 1, characterized in that, The curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.9 < (R1 + R2) / (R1 - R2) < 1.

3.

7. The optical lens according to claim 1, characterized in that, The curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: -8.3 < (R7 + R8) / (R7 - R8) < 19.

8. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.9 < f1 / f2 < -0.

6.

9. The optical lens according to claim 1, characterized in that, The clear aperture radius DM12 of the image side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 1.6 < 2×DM12 / R2 < 2.

10. The optical lens according to claim 1, characterized in that, The Abbe number Vd3 of the third lens and the Abbe number Vd4 of the fourth lens satisfy: 30 < Vd3 - Vd4 < 36.

Images