Optical lens

Abstract

The invention provides an optical lens, which comprises six lenses which sequentially comprise 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 image side along an optical axis, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has focal power; the sixth lens has negative focal power, and the object side surface of the sixth lens is a convex surface near the optical axis; wherein the actual image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens and the maximum field angle FOV of the optical lens meet the following conditions: 0.8 lt; (IH / 2) / (f * tan (FOV / 2)) lt; and 0.95%. The optical lens provided by the invention has one or more advantages of miniaturization, large aperture, large image height, large field angle and the like.

Description

Technical Field

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

[0002] In recent years, the autonomous driving sector has developed rapidly both domestically and internationally. Automotive ADAS lenses are crucial components of driver assistance systems, and their optical performance is crucial. Existing ADAS lenses suffer from high costs, low image clarity, and low relative illumination, resulting in poor image uniformity.

[0003] In order to solve the defects and shortcomings of the existing technology, the purpose of this design is to provide an on-board ADAS optical lens with a simple structure, reasonable design and easy use. It adopts two spherical lenses made of glass and four aspherical lenses made of plastic. Its structure is simple and easy to assemble, which greatly reduces the manufacturing cost and processing difficulty, is conducive to mass production, can adapt to different environments, and has high overall reliability. Summary of the Invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0005] The technical solution adopted in the present invention is:

[0006] An optical lens, comprising six lenses, including the following lenses in order from the object side to the imaging surface along the optical axis:

[0007] The first lens has a negative optical power, its object-side surface is convex and its image-side surface is concave;

[0008] a second lens having negative optical power, whose object-side surface is concave and whose image-side surface is convex;

[0009] a third lens element having positive optical power, whose object-side surface is convex and whose image-side surface is convex;

[0010] a fourth lens element having positive refractive power, whose object-side surface is convex and whose image-side surface is convex;

[0011] a fifth lens having optical power;

[0012] a sixth lens element having negative optical power, the object side surface of which is convex near the optical axis;

[0013] The real image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens and the maximum field angle FOV of the optical lens satisfy the following conditions: 0.8<(IH / 2) / (f×tan(FOV / 2))<0.95.

[0014] Further preferably, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens meet the following requirements: 9.4 mm <TTL / Fno<11.2mm。

[0015] Further preferably, 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 the following relationship: 1.8 <IH / EPD<2.9。

[0016] Further preferably, the maximum field of view FOV of the optical lens and the chief ray incidence angle CRA at the maximum image height of the optical lens satisfy: 3≤FOV / CRA<4.1.

[0017] Further preferably, a curvature radius R1 of the object side surface of the first lens and a curvature radius R2 of the image side surface of the first lens satisfy: 2<(R1+R2) / (R1-R2)<4.5.

[0018] Further preferably, the vector height SAGX11 corresponding to the maximum clear semi-aperture of the object side end of the first lens and the center thickness CT1 of the first lens on the optical axis meet the following conditions: 0.5 <SAGX11 / CT1<1.2。

[0019] Further preferably, the focal length f2 of the second lens, the object side curvature radius R3 of the second lens and the image side curvature radius R4 of the second lens satisfy: 1.3 <f2 / (R3+R4)<5.9。

[0020] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.7 <f1 / f<-1.6。

[0021] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1 <f3 / f<3.5。

[0022] Further preferably, the combined focal length f456 of the fourth lens, the fifth lens, and the sixth lens and the effective focal length f of the optical lens satisfy the following equation: 1.6 <f456 / f<2.3。

[0023] The optical lens provided by the present invention uses six lenses with specific optical powers. Through the combination of specific surface shapes and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, so that the lens has one or more advantages such as miniaturization, large aperture, large image height, and wide field of view. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which:

[0025] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0026] Figure 2 Graph showing the field curvature of the optical lens in Example 1 of the present invention.

[0027] Figure 3 2 is a distortion curve diagram of the optical lens in Example 1 of the present invention.

[0028] Figure 4 Graph showing longitudinal chromatic aberration of the optical lens in Example 1 of the present invention.

[0029] Figure 5 Graph showing vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0030] Figure 6 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0031] Figure 7 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0032] Figure 8 This is a distortion curve diagram of the optical lens in Example 2 of the present invention.

[0033] Figure 9 Graph showing longitudinal chromatic aberration of the optical lens in Example 2 of the present invention.

[0034] Figure 10 Graph showing vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0035] Figure 11 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0036] Figure 12 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0037] Figure 13 3 is a distortion curve diagram of the optical lens in Example 3 of the present invention.

[0038] Figure 14 Graph showing longitudinal chromatic aberration of the optical lens in Example 3 of the present invention.

[0039] Figure 15 Graph showing vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0040] Figure 16 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0041] Figure 17 4 is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0042] Figure 18 This is a distortion curve diagram of the optical lens in Example 4 of the present invention.

[0043] Figure 19 Graph showing longitudinal chromatic aberration of the optical lens in Example 4 of the present invention.

[0044] Figure 20 Graph showing vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0045] Figure 21 Schematic diagram of the structure of the optical lens in Example 5 of the present invention.

[0046] Figure 22 4 is a field curvature curve diagram of the optical lens in Example 5 of the present invention.

[0047] Figure 23 This is a distortion curve diagram of the optical lens in Example 5 of the present invention.

[0048] Figure 24 Graph showing longitudinal chromatic aberration of the optical lens in Example 5 of the present invention.

[0049] Figure 25 Graph showing vertical axis chromatic aberration of the optical lens in Example 5 of the present invention.

[0050] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0051] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of embodiments of the present application and are not intended to limit the scope of the present 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.

[0052] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0053] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0054] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, 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.

[0055] It should also be understood that the terms "comprises," "including," "having," "includes," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application." And, the term "exemplary" is intended to refer to an example or illustration.

[0056] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0057] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0058] An optical lens provided by an embodiment of the present invention includes six lenses, which are, in order from the object side to the imaging surface along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens.

[0059] 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 negative optical power, its object-side surface may be concave, and its image-side surface may be convex. The third lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The fourth lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The fifth lens may have positive optical power or negative optical power, its object-side surface may be concave or convex; its image-side surface may be convex or concave at the near optical axis. The sixth lens may have negative optical power, its object-side surface may be convex at the near optical axis, and its image-side surface may be concave or convex at the near optical axis. More specifically, the fifth lens element may have positive optical power, its object-side surface may be concave, and its image-side surface may be convex near the optical axis; the fifth lens element may have negative optical power, its object-side surface may be convex, and its image-side surface may be concave; the fifth lens element may have negative optical power, its object-side surface may be concave, and its image-side surface may be concave.

[0060] In some embodiments, the optical lens may further include an aperture, which may be located between the third and fourth lens elements. It is understood that the aperture is used to limit the amount of light entering, thereby changing the brightness of the image. When the aperture is located between the third and fourth lens elements, it facilitates correction of aperture aberrations.

[0061] In some embodiments, the optical lens may further include a filter and a protective glass, positioned sequentially along the optical axis between the sixth lens and the imaging plane. The filter is used to filter out interfering light, preventing it from reaching the imaging plane of the optical lens and affecting normal imaging. The protective glass protects the optical lens from damage to the photosensitive chip and improves the optical lens's impact and scratch resistance, while having little impact on the imaging quality of the optical lens.

[0062] In some embodiments, the fourth lens and the fifth lens may be cemented together to form a cemented lens, or the fifth lens and the sixth lens may be cemented together to form a cemented lens. This can effectively correct chromatic aberration of the optical lens, reduce the decentration sensitivity of the optical lens, balance the aberrations of the optical lens, and improve the imaging quality of the optical lens. It can also reduce the assembly sensitivity of the optical lens, thereby reducing the difficulty of the optical lens processing and improving the assembly yield of the optical lens.

[0063] 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 maximum field angle FOV of the optical lens satisfy: 0.8 < (IH / 2) / (f × tan(FOV / 2)) < 0.95. Meeting the above range enables the optical lens to have a large field angle while also achieving the characteristic of a large image height, which is beneficial for the optical lens to match a larger-sized photosensitive chip, avoid vignetting, and improve the relative illumination of the optical lens. At the same time, it can effectively increase the proportion of the edge field of the optical lens in the entire image plane, control the edge distortion of the optical lens, and improve the imaging quality of the optical lens.

[0064] In some embodiments, the overall optical length TTL of the optical lens and the f-number Fno of the optical lens satisfy: 9.4 mm < TTL / Fno < 11.2 mm. Meeting the above range, by controlling the relationship between the overall length and the f-number of the optical lens, it is ensured that the optical lens can meet the design requirements of a large aperture and miniaturization, enabling the optical lens to obtain sufficient light transmission in a dim environment and meet the shooting needs of high image quality and high definition.

[0065] 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: 1.8 < IH / EPD < 2.9. Meeting the above range can make the optical lens with a large image plane have a larger entrance pupil diameter and higher light transmission, thereby increasing the imaging effect when the optical lens works in a dark environment and reducing the aberration of the edge field of view.

[0066] In some embodiments, the maximum field angle FOV of the optical lens and the chief ray angle of incidence CRA at the maximum image height of the optical lens satisfy: 3 ≤ FOV / CRA < 4.1. Meeting the above range is beneficial for the optical lens to meet the large-range shooting requirements. At the same time, it is also beneficial to reduce the angle of incidence of the chief ray on the imaging plane, making it easier for the optical lens to cooperate with the photosensitive element, improving the photosensitive performance, and further improving the relative illumination of the optical lens.

[0067] In some embodiments, the curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: 2 < (R1 + R2) / (R1 - R2) < 4.5. Meeting the above range, reasonably limiting the surface type of the first lens can reduce the distortion generated by the first lens, thereby reducing the difficulty of subsequent lens distortion correction, and helping to improve the imaging quality. At the same time, it can ensure that the first lens converges more incident light and improves the imaging brightness of the optical lens.

[0068] In some embodiments, the sagittal height SAGX11 corresponding to the maximum clear aperture semi-diameter at the object side end of the first lens and the central thickness CT1 of the first lens on the optical axis satisfy: 0.5 < SAGX11 / CT1 < 1.2. Meeting the above range can make the surface shape of the object side face tend to be curved. At the same time, a larger sagittal height is beneficial for the first lens to collect light rays in a large field of view, achieving high angular resolution at the center of the optical lens, and thus improving the imaging quality of the central region.

[0069] In some embodiments, the focal length f2 of the second lens, the curvature radius R3 of the object side face of the second lens, and the curvature radius R4 of the image side face of the second lens satisfy: 1.3 < f2 / (R3 + R4) < 5.9. Meeting the above range can constrain the surface shapes of the object side face and the image side face of the second lens, which is beneficial for reducing the bending degree of light rays at the image side face of the second lens, reducing the astigmatism of the optical lens, so as to balance the astigmatism problem brought by the large field of view angle of the optical lens, making the astigmatism not too large while the optical lens has a large field of view, and thus ensuring that the optical lens has excellent imaging quality.

[0070] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.7 < f1 / f < -1.6. Meeting the above range, it is defined that the first lens has a negative optical power, which can capture the light rays entering the optical lens at large angles, expand the field of view angle range of the optical lens, and is beneficial for reducing the sensitivity of the optical lens and realizing the miniaturized design of the optical lens.

[0071] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1 < f3 / f < 3.5. Meeting the above range, it is defined that the third lens has a positive optical power and defines the proportion of the optical power of the third lens, which is beneficial for adjusting the light ray trends from the first lens and the second lens, making the optical lens have the characteristics of a large field of view angle, low sensitivity and miniaturization.

[0072] In some embodiments, the combined focal length f456 of the fourth lens, the fifth lens, and the sixth lens and the effective focal length f of the optical lens satisfy: 1.6 < f456 / f < 2.3. Meeting the above range is beneficial for controlling the height of the light rays exiting the optical lens, reducing the aberration of the marginal field of view, and at the same time can correct the influence of the field curvature generated by the previous lenses on the resolution, improving the imaging quality of the optical lens.

[0073] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 33° < FOV / Fno < 43°. Meeting the above range, reasonably defining the ratio of the field of view angle to the aperture value, can collect light rays at large angles and obtain good imaging quality.

[0074] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1 < IH / f < 1.5. Meeting the above range can achieve the large image plane characteristic of the lens, can match a large-size chip, and enable the optical lens to achieve high-pixel imaging.

[0075] In some embodiments, the curvature radius R1 of the object side surface of the first lens and the sagitta SAGX11 corresponding to the maximum clear aperture radius at the object side end of the first lens satisfy: 4 < R1 / SAGX11 < 28. Meeting the above range can make large-angle light converge into the optical lens, effectively expanding the field angle of the optical lens.

[0076] In some embodiments, the central thickness CT1 of the first lens on the optical axis, the central thickness CT2 of the second lens on the optical axis, the central thickness CT3 of the third lens on the optical axis, the distance CT12 between the first lens and the second lens on the optical axis, and the distance CT23 between the second lens and the third lens on the optical axis satisfy: 1 < (CT1 + CT2 + CT3) / (CT12 + CT23) < 2.2. Meeting the above range can effectively control the deflection of marginal large-field light, improving the relative illumination of the optical lens. It can also effectively control the reasonable distribution of the first three lenses in space, ensuring that the optical lens has better assembly performance and improving the production yield.

[0077] In some embodiments, the central thickness CT2 of the second lens on the optical axis and the edge thickness ET2 of the second lens satisfy: 0.6 < CT2 / ET2 < 1. Meeting the above range can effectively balance the aberration generated by the optical lens. At the same time, it is beneficial to the field curvature adjustment in engineering production, and thus beneficial to improving the imaging quality of the optical lens.

[0078] In some embodiments, the optical lens satisfies the following conditional expressions: 17 mm ≤ TTL ≤ 20 mm; 1.8 ≤ Fno ≤ 2; 6 mm ≤ IH < 7 mm; 60° ≤ FOV < 82°. In the above conditional expressions, FOV represents the maximum field angle of the optical lens, TTL represents the overall optical length of the optical lens, Fno represents the aperture value of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. Meeting the above range, the optical lens has at least one or more advantages such as miniaturization, large aperture, large image height, and large field angle.

[0079] In some embodiments, the lens material in the optical lens provided by the present invention may be glass or plastic. When the material of the lens is plastic, the production cost can be effectively reduced. On the other hand, when the material of the lens is glass, the low dispersion characteristic of the glass itself can be used to effectively correct the geometric chromatic aberration of the optical system. The optical lens provided by the present invention adopts a lens structure of six glass-plastic hybrids. More specifically, the first lens can be a glass lens, the second lens, the fifth lens, and the sixth lens can be plastic lenses, and the third lens and the fourth lens can be glass lenses or plastic lenses. The use of a glass-plastic hybrid structure can improve thermal stability, effectively reduce costs, correct aberrations, reduce volume, and provide a more cost-effective optical lens product.

[0080] In some embodiments, the first, second, third, fourth, fifth, and sixth lenses may be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce the aberrations of the optical system, thereby reducing the number and size of lenses and achieving better miniaturization. More specifically, in the optical lens provided by the present invention, the first lens may be a spherical lens, the second, fifth, and sixth lenses may be aspherical lenses, and the third and fourth lenses may be spherical or aspherical lenses.

[0081] In various embodiments of the present invention, when the lens is an aspheric lens, the shapes of the aspheric surfaces of the optical lens satisfy the following equations:

[0082]

[0083] Where z is the distance between the surface and the vertex in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, and B, C, D, E, F, G, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients, respectively.

[0084] The present invention is further illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0085] Example 1

[0086] See also Figure 1, shown is a schematic structural diagram of the optical lens 100 provided in Example 1 of the present invention. The optical lens 100 includes, in order from the object side to the imaging surface along the optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a filter G1 and a protective glass G2.

[0087] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0088] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0089] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is convex;

[0090] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is convex;

[0091] The fifth lens L5 has positive refractive power, its object-side surface S8 is concave, and its image-side surface S9 is convex;

[0092] The fourth lens L4 and the fifth lens L5 form a cemented lens group, that is, the cemented surface between the image-side surface of the fourth lens L4 and the object-side surface of the fifth lens L5 is S8;

[0093] The sixth lens L6 has negative refractive power, its object-side surface S10 is convex near the optical axis, and its image-side surface S11 is concave near the optical axis;

[0094] The object side surface S12 and the image side surface S13 of the filter G1 are both flat surfaces;

[0095] The object side surface S14 and the image side surface S15 of the protective glass G2 are both flat surfaces;

[0096] The imaging surface S16 is a plane.

[0097] The first lens L1 and the third lens L3 are glass spherical lenses, and the second lens L2, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are plastic aspherical lenses.

[0098] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0099] Table 1-1

[0100]

[0101]

[0102] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0103] Table 1-2

[0104]

[0105] In this embodiment, the field curvature curve, distortion curve, longitudinal chromatic aberration curve, and vertical axis chromatic aberration curve of the optical lens 100 are shown as follows: Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 shown.

[0106] Figure 2 A field curvature graph of the optical lens 100 in this embodiment is shown, showing the field curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the graph, the field curvature in the meridional and sagittal image planes is controlled within ±0.03mm, indicating that the optical lens 100 can effectively correct field curvature.

[0107] Figure 3 A distortion curve for the optical lens 100 of this embodiment is shown, representing the distortion at different field angles on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the distortion value is controlled within a range of -10% to 0%, and the image compression in the edge angle area is relatively smooth, effectively improving the clarity of the expanded image.

[0108] Figure 4 A longitudinal chromatic aberration curve for the optical lens 100 of this embodiment is shown. It shows the chromatic aberration at various wavelengths along the optical axis at the imaging plane. The horizontal axis represents the longitudinal chromatic aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the graph, the offset of the longitudinal chromatic aberration is controlled within a range of -0.012 mm to 0.016 mm, indicating that the optical lens 100 can effectively correct longitudinal chromatic aberration.

[0109] Figure 5 A graph of vertical chromatic aberration for the optical lens 100 in this embodiment is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.546 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within a range of -2 μm to 3 μm, demonstrating that the optical lens 100 is capable of effectively correcting vertical chromatic aberration.

[0110] Example 2

[0111] See also Figure 6, shown is a schematic structural diagram of an optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, this embodiment has the following main differences: the fifth lens element L5 has negative optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave; the fifth lens element L5 and the sixth lens element L6 form a cemented lens group, that is, the cemented surface of the image-side surface of the fifth lens element L5 and the object-side surface of the sixth lens element L6 is S10; the third lens element L3 is a plastic aspheric lens; the fourth lens element L4 is a glass spherical lens; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0112] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0113] Table 2-1

[0114]

[0115] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0116] Table 2-2

[0117]

[0118]

[0119] In this embodiment, the field curvature curve, distortion curve, longitudinal chromatic aberration curve, and vertical axis chromatic aberration curve of the optical lens 200 are shown as follows: Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 As shown. Figure 7 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.05mm to 0.04mm, indicating that the optical lens 200 can well correct the field curvature. Figure 8 It can be seen from the figure that the distortion value is controlled within -20% to 0%, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the expanded image. Figure 9 It can be seen from the figure that the offset of longitudinal chromatic aberration is controlled within the range of -0.008mm to 0.016mm, indicating that the optical lens 200 can correct longitudinal chromatic aberration well. Figure 10 It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -4μm to 12μm, indicating that the optical lens 200 can better correct the vertical axis chromatic aberration.

[0120] Example 3

[0121] See also Figure 11, shown is a schematic structural diagram of an optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S9 of the fifth lens L5 is convex at the near optical axis; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0122] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0123] Table 3-1

[0124]

[0125]

[0126] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0127] Table 3-2

[0128]

[0129] In this embodiment, the field curvature curve, distortion curve, longitudinal chromatic aberration curve, and vertical axis chromatic aberration curve of the optical lens 300 are shown as follows: Figure 12 、 Figure 13 、 Figure 14 、 Figure 15 As shown. Figure 12 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.02mm to 0.03mm, indicating that the optical lens 300 can well correct the field curvature. Figure 13 It can be seen that the distortion value is controlled within -16% to 0%, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the expanded image. Figure 14 It can be seen from the figure that the offset of longitudinal chromatic aberration is controlled within the range of -0.008mm to 0.012mm, indicating that the optical lens 300 can correct longitudinal chromatic aberration well. Figure 15 It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -2μm to 4μm, indicating that the optical lens 300 can better correct the vertical axis chromatic aberration.

[0130] Example 4

[0131] See also Figure 16 , shown is a schematic structural diagram of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, the main difference between this embodiment is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0132] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0133] Table 4-1

[0134]

[0135]

[0136] The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0137] Table 4-2

[0138]

[0139] In this embodiment, the field curvature curve, distortion curve, longitudinal chromatic aberration curve, and vertical axis chromatic aberration curve of the optical lens 400 are shown as follows: Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 As shown. Figure 17 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.04mm to 0.08mm, indicating that the optical lens 400 can well correct the field curvature. Figure 18 It can be seen from the figure that the distortion value is controlled within -8% to 0%, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the expanded image. Figure 19 It can be seen from the figure that the offset of longitudinal chromatic aberration is controlled within ±0.016mm, indicating that the optical lens 400 can correct longitudinal chromatic aberration well. Figure 20 It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -2μm to 4μm, indicating that the optical lens 400 can better correct the vertical axis chromatic aberration.

[0140] Example 5

[0141] See also Figure 21 , shown is a schematic structural diagram of an optical lens 500 provided in Example 5 of the present invention. Compared with Example 1, this embodiment has the following main differences: the fifth lens element L5 has negative optical power, and its image-side surface S10 is concave; the image-side surface S11 of the sixth lens element L6 is convex; the fifth lens element L5 and the sixth lens element L6 form a cemented lens group, that is, the cemented surface S10 of the image-side surface of the fifth lens element L5 and the object-side surface of the sixth lens element L6; the third lens element L3 is a plastic aspherical lens; the fourth lens element L4 is a glass spherical lens; and the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0142] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0143] Table 5-1

[0144]

[0145] The surface parameters of the aspheric lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0146] Table 5-2

[0147]

[0148] In this embodiment, the field curvature curve, distortion curve, longitudinal chromatic aberration curve, and vertical axis chromatic aberration curve of the optical lens 500 are shown as follows: Figure 22 、 Figure 23 、 Figure 24 、 Figure 25 As shown. Figure 22 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.03mm to 0.04mm, indicating that the optical lens 500 can correct the field curvature well. Figure 23 It can be seen that the distortion value is controlled within -16% to 0%, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the expanded image. Figure 24 It can be seen from the figure that the offset of longitudinal chromatic aberration is controlled within ±0.016mm, indicating that the optical lens 500 can correct longitudinal chromatic aberration well. Figure 25 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -2μm to 8μm, indicating that the optical lens 500 can better correct the vertical axis chromatic aberration.

[0149] Please refer to Table 6, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, chief ray incidence angle CRA at maximum image height, real image height IH corresponding to maximum field of view angle, maximum field of view angle FOV, entrance pupil diameter EPD of the optical lens, and the numerical value corresponding to each conditional expression in each embodiment.

[0150] Table 6

[0151] Parameters and Conditionals Example 1 Example 2 Example 3 Example 4 Example 5 f(mm) 5.80 4.44 4.43 6.46 4.35 FOV(°) 60.00 81.25 76.11 60.00 77.32 EPD(mm) 3.22 2.22 2.33 3.59 2.42 TTL(mm) 17.00 20.00 19.65 18.00 20.00 Fno 1.80 2.00 1.90 1.80 1.80 IH(mm) 6.11 6.30 6.00 6.89 6.00 CRA(°) 20.00 20.00 20.00 20.00 19.34 TTL / Fno(mm) 9.44 10.00 10.34 10.00 11.11 (IH / 2) / (f×tan(FOV / 2)) 0.91 0.83 0.86 0.92 0.86 IH / EPD 1.90 2.84 2.57 1.92 2.48 FOV / Fno(°) 33.33 40.62 40.06 33.33 42.96 IH / f 1.05 1.42 1.35 1.07 1.38 FOV / CRA 3.00 4.06 3.81 3.00 4.00 (R1+R2) / (R1-R2) 4.35 2.01 3.13 2.53 2.40 R1 / SAGX11 5.73 9.03 4.48 27.96 5.14 SAGX11 / CT1 1.02 1.09 1.16 0.72 0.63 f2 / (R3+R4) 1.97 1.35 1.44 2.22 5.85 f1 / f -3.69 -1.99 -2.65 -2.98 -1.63 f3 / f 1.20 1.56 1.55 1.07 3.44 f456 / f 1.85 1.62 2.28 2.27 1.65 (CT1+CT2+CT3) / (CT12+CT23) 1.35 1.04 1.61 1.39 2.15 CT2 / ET2 0.64 0.64 0.70 0.61 0.93

[0152] In summary, the optical lens provided by the present invention uses six lenses with specific optical powers. Through the combination of specific surface shapes and reasonable optical power distribution, it is possible to improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages such as miniaturization, large aperture, large image height, and large field of view.

[0153] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0154] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, comprising six lenses, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: The first lens has a negative optical power, its object-side surface is convex and its image-side surface is concave; a second lens having negative optical power, whose object-side surface is concave and whose image-side surface is convex; a third lens element having positive optical power, whose object-side surface is convex and whose image-side surface is convex; a fourth lens element having positive refractive power, whose object-side surface is convex and whose image-side surface is convex; a fifth lens having optical power; a sixth lens element having negative optical power, the object side surface of which is convex near the optical axis; The real image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens and the maximum field angle FOV of the optical lens satisfy the following conditions: 0.8<(IH / 2) / (f×tan(FOV / 2))<0.

95.

2. The optical lens according to claim 1, wherein: The total optical length TTL of the optical lens and the aperture value Fno of the optical lens meet the following requirements: 9.4 mm <TTL / Fno<11.2mm。 3. The optical lens according to claim 1, wherein: 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 meet the following requirements: 1.8 <IH / EPD<2.9。 4. The optical lens according to claim 1, wherein: The maximum field of view FOV of the optical lens and the chief ray incidence angle CRA at the maximum image height of the optical lens satisfy the following conditions: 3≤FOV / CRA<4.

1.

5. The optical lens according to claim 1, wherein: A curvature radius R1 of the object side surface of the first lens and a curvature radius R2 of the image side surface of the first lens satisfy: 2<(R1+R2) / (R1-R2)<4.

5.

6. The optical lens according to claim 1, wherein: The vector height SAGX11 corresponding to the maximum light semi-aperture at the object side end of the first lens and the center thickness CT1 of the first lens on the optical axis meet the following conditions: 0.5 <SAGX11 / CT1<1.2。 7. The optical lens according to claim 1, wherein: The focal length f2 of the second lens, the object side curvature radius R3 of the second lens and the image side curvature radius R4 of the second lens satisfy: 1.3 <f2 / (R3+R4)<5.9。 8. The optical lens according to claim 1, wherein: The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.7 <f1 / f<-1.6。 9. The optical lens according to claim 1, wherein: The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1 <f3 / f<3.5。 10. The optical lens according to claim 1, wherein: The combined focal length f456 of the fourth lens, the fifth lens, and the sixth lens and the effective focal length f of the optical lens satisfy: 1.6 <f456 / f<2.3。

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