Optical lens

Abstract

This invention provides an optical lens comprising seven lenses, arranged sequentially along the optical axis from the object side to the image plane: a first lens with negative power, both its object side and image side being concave; a second lens with positive power, its object side being concave and its image side being convex; a third lens with negative power, its object side being concave and its image side being convex; a fourth lens with positive power, its object side being convex and its image side being convex; a fifth lens with negative power, its image side being concave; a sixth lens with positive power, its object side being convex and its image side being convex; and a seventh lens with negative power, its object side being concave and its image side being convex. This invention achieves a large field of view, a large aperture, and miniaturization by rationally combining the lens shapes and power of each lens.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, and in particular to an optical lens. Background Technology

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] The intelligent cockpit, also known as an intelligent vehicle occupant monitoring system (OMS), is designed to ensure not only driver safety but also the safety and passenger experience of those inside the vehicle. Beyond cabin safety, passenger comfort is another crucial aspect of the intelligent cockpit's existence. Currently, intelligent vehicle occupant monitoring systems (OMS) on the market require a wide field of view and high optical performance, thus often employing an all-glass structure and resulting in a large size. This hinders the integration of optical lenses and reduces costs. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide an optical lens that can solve at least one or more of the above problems.

[0005] To achieve the above objectives, the present invention provides an optical lens comprising seven lenses, arranged sequentially along the optical axis from the object side to the image plane: a first lens with negative optical power, having a concave object side and a concave image side; a second lens with positive optical power, having a concave object side and a convex image side; a third lens with negative optical power, having a concave object side and a convex image side; a fourth lens with positive optical power, having a convex object side and a convex image side; a fifth lens with negative optical power, having a concave image side; a sixth lens with positive optical power, having a convex object side and a convex image side; and a seventh lens with negative optical power, having a concave object side and a convex image side.

[0006] In some embodiments, the fifth lens and the sixth lens are cemented together to form a cemented lens.

[0007] In some implementations, the aperture stop is positioned between the third lens and the fourth lens.

[0008] In some implementations, the aperture value FNO of the optical lens satisfies: 1.90 < FNO < 2.10.

[0009] In some implementations, the maximum field of view (FOV) of the optical lens satisfies: 170° < FOV.

[0010] In some implementations, the incident angle CRA of the principal ray at the maximum field of view of the optical lens on the image plane satisfies: 22° < CRA < 32°.

[0011] In some implementations, the total optical length (TTL) of the optical lens and the effective focal length (f) of the optical lens satisfy the condition: TTL / f < 4.0.

[0012] In some implementations, the total optical length TTL of the optical lens and the image height IH corresponding to the maximum field of view of the optical lens satisfy: TTL / IH < 2.3.

[0013] In some implementations, the effective focal length f of the optical lens, the maximum field of view (FOV) of the optical lens, and the image height IH corresponding to the maximum field of view of the optical lens satisfy: f*FOV / IH < 100.0.

[0014] In some embodiments, the light transmission aperture D1 of the object side of the first lens and the image height IH corresponding to the maximum field of view of the optical lens satisfy the following condition: 0.9 < D1 / IH < 1.2.

[0015] In some implementations, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < -2.2.

[0016] In some implementations, the effective focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: f3 / f < -1.5.

[0017] In some implementations, the effective focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: f7 / f < -0.6.

[0018] In some embodiments, the radius of curvature R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: R1 / f < -30.0.

[0019] In some embodiments, the radius of curvature R3 of the side surface of the second lens and the effective focal length f of the optical lens satisfy: R3 / f < -5.5.

[0020] In some embodiments, the radius of curvature R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: R5 / f < -0.5.

[0021] In some embodiments, the radius of curvature R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: R12 / f < -1.0.

[0022] In some embodiments, the radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: 1.1 < (R1-R2) / (R1+R2).

[0023] In some embodiments, the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: 0.5 < (R3-R4) / (R3+R4) < 0.7.

[0024] In some embodiments, the radius of curvature R5 of the object side of the third lens and the radius of curvature R6 of the image side of the third lens satisfy: -0.6 < (R5-R6) / (R5+R6) < -0.3.

[0025] In some embodiments, the radius of curvature R13 of the object side of the seventh lens and the radius of curvature R14 of the image side of the seventh lens satisfy: -0.8 < (R13-R14) / (R13+R14) < -0.1.

[0026] In some embodiments, the half-aperture sagitta Sag3 of the object-side surface of the second lens and the half-aperture d3 of the object-side surface of the second lens satisfy: -0.15 <Sag3 / d3<-0.10。

[0027] In some embodiments, the image-side half-aperture sagitta Sag4 of the second lens and the image-side half-aperture d4 of the second lens satisfy: -0.25 <Sag4 / d4<-0.15。

[0028] In some embodiments, the object-side aperture half-aperture sagitta Sag5 of the third lens and the object-side aperture half-aperture d5 of the third lens satisfy: -0.25 <Sag5 / d5<-0.20。

[0029] In some embodiments, the image-side aperture sag12 of the sixth lens and the image-side aperture d12 of the sixth lens satisfy: -0.25 <Sag12 / d12<-0.03。

[0030] In some embodiments, the sum of the center thicknesses of the first to seventh lenses, ∑CT, satisfies the condition that the total optical length of the optical lens, TTL, is 0.60 < ∑CT / TTL < 0.70.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: The optical lens provided by the present invention uses seven lenses with optical power. By reasonably matching the optical power and surface shape of each lens, the optical lens has a compact structure and good image quality. At the same time, by reasonably setting the aperture position, lens thickness and inter-lens spacing, the optical lens has a large field of view and a large aperture, achieving a balance between a large field of view, a large aperture, miniaturization and high pixel count, which can meet the imaging requirements of automotive lenses. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the optical lens in Embodiment 1 of the present invention.

[0033] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0034] Figure 3 This is a relative illumination curve of the optical lens in Embodiment 1 of the present invention.

[0035] Figure 4 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0036] Figure 5 This is a schematic diagram of the optical lens structure of Embodiment 2 of the present invention.

[0037] Figure 6 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0038] Figure 7 This is a relative illumination curve of the optical lens in Embodiment 2 of the present invention.

[0039] Figure 8 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0040] Figure 9 This is a schematic diagram of the optical lens structure of Embodiment 3 of the present invention.

[0041] Figure 10 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0042] Figure 11 This is a relative illumination curve of the optical lens in Embodiment 3 of the present invention.

[0043] Figure 12 This is an MTF curve of the optical lens in Embodiment 3 of the present invention. Detailed Implementation

[0044] To better understand the invention, various aspects of the invention 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 the invention and are not intended to limit the scope of the invention 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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 the invention, the word "may" is used to mean "one or more embodiments of the invention." And the term "exemplary" is intended to refer to an example or illustration.

[0049] 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 invention 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 defined herein.

[0050] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0051] This invention provides an optical lens, which, from the object side to the imaging plane, includes, in sequence, a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and a filter, and the optical centers of each lens are located on the same straight line.

[0052] In some embodiments, the first lens is configured to have negative optical power, with both the object-side and image-side surfaces being concave. This can reduce the overall length of the lens and help reduce axial and radial astigmatism, resulting in clearer and sharper images and improving the imaging quality of the optical lens.

[0053] In some embodiments, the second lens is configured to have positive optical power, with the object side being concave and the image side being convex. This can effectively constrain large-angle light rays passing through the first lens, slow down the light refracting trend and make it transition smoothly, while also balancing the aberrations generated by the first lens and reducing the sensitivity of the optical lens.

[0054] In some embodiments, the third lens is configured to have negative optical power, with the object side being concave and the image side being convex. This facilitates better control of the beam path and distribution, allowing light to pass through the aperture more uniformly and effectively improving the uniformity of the image formed by the optical lens.

[0055] In some embodiments, the fourth lens is configured to have positive optical power, and the object side and image side are convex to further converge light rays, reduce the light ray height, and make the light ray path transition smoothly. At the same time, it can balance the spherical aberration and field curvature generated by the front lens and improve the imaging quality of the optical lens.

[0056] In some embodiments, the fifth lens and the sixth lens can be cemented together to form a cemented lens, which is used to share the chromatic aberration correction of the optical lens and improve the resolution of the optical lens. The fifth lens is configured to have negative optical power and a concave image side, while the sixth lens is configured to have positive optical power and a convex object side and an convex image side. This can converge the light rays emitted from the fourth lens and make them transition smoothly. At the same time, it can correct various aberrations caused by the front lens, reduce the loss of light in each field of view, improve the relative illumination of each field of view, and thus improve the imaging quality of the optical lens.

[0057] In some embodiments, the seventh lens is configured to have negative optical power, with the object side being concave and the image side being convex, which is beneficial to increasing the imaging area of ​​the optical lens and improving the imaging quality of the optical lens.

[0058] In some embodiments, an aperture stop can be positioned between the third and fourth lenses to narrow the range of light emitted from the front lens, reduce the aperture of the rear lens, and balance the structure of the front and rear lens groups.

[0059] In some implementations, the aperture value FNO of the optical lens satisfies the following condition: 1.90 < FNO < 2.10. Meeting this range is beneficial for achieving large aperture characteristics, ensuring image clarity even in low-light environments or at night.

[0060] In some implementations, the maximum field of view (FOV) of the optical lens satisfies: 170° < FOV. Meeting this range facilitates the achievement of wide-angle characteristics, thereby enabling the acquisition of more scene information and meeting the needs of large-area detection.

[0061] In some implementations, the incident angle CRA of the principal ray at the maximum field of view of the optical lens on the image plane satisfies: 22° < CRA < 32°. Satisfying this range allows for a larger tolerance range between the CRA of the optical lens and the CRA of the image sensor, improving the adaptability of the optical lens to the image sensor.

[0062] In some implementations, the total optical length (TTL) of the optical lens and the effective focal length (f) of the optical lens satisfy the condition: TTL / f < 4.0. Meeting this range can effectively limit the length and volume of the optical lens, enabling miniaturization of the optical lens.

[0063] In some implementations, the total optical length (TTL) of the optical lens and the image height (IH) corresponding to the maximum field of view of the optical lens satisfy the condition: TTL / IH < 2.3. Meeting this range enables large-area imaging with the optical lens while simultaneously shortening the total optical length, thereby achieving a balance between optical lens miniaturization and large-area imaging, and enhancing market competitiveness.

[0064] In some implementations, the effective focal length f of the optical lens, the maximum field of view (FOV) of the optical lens, and the image height IH corresponding to the maximum field of view of the optical lens satisfy the condition: f*FOV / IH < 100.0. Meeting this range ensures that the field of view is increased while maintaining the same image plane size, achieving greater distortion, i.e., increasing the angular resolution of the central region.

[0065] In some embodiments, the light-transmitting aperture D1 of the object-side surface of the first lens and the image height IH corresponding to the maximum field of view of the optical lens satisfy the condition: 0.9 < D1 / IH < 1.2. Satisfying the above range can balance the relationship between the front aperture of the optical lens and the image plane.

[0066] In some embodiments, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < -2.2. Satisfying this range allows the first lens to have appropriate negative optical power, which helps to make the change in the refraction angle of the incident light more gradual, avoids excessive refraction changes that would produce too many aberrations, and at the same time helps more light to enter the rear lens, increasing the field of view of the optical lens and improving the relative illumination of the optical lens.

[0067] In some embodiments, the effective focal length f3 of the third lens and the effective focal length f of the optical lens satisfy the condition: f3 / f < -1.5. Satisfying this range allows the third lens to have appropriate negative optical power, which is beneficial for expanding the effective field of view of the optical lens, allowing more light to enter the optical lens, while better controlling the path and distribution of the light beam, making the light pass through the aperture more uniformly, and effectively improving the uniformity of the image formed by the optical lens.

[0068] In some embodiments, the effective focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy the condition: f7 / f < -0.6. Satisfying this range allows the seventh lens to have an appropriate negative optical power, which is beneficial for increasing the angle of incidence of light entering the imaging plane, further increasing the imaging area of ​​the optical lens, and realizing large target surface imaging of the optical lens.

[0069] In some embodiments, the radius of curvature R1 of the side surface of the first lens and the effective focal length f of the optical lens satisfy: R1 / f < -30.0. Satisfying the above range can effectively control the surface curvature of the side surface of the first lens, increase the field of view while controlling the front diameter of the optical lens, and also benefit the overall length of the optical lens.

[0070] In some embodiments, the radius of curvature R3 of the side surface of the second lens and the effective focal length f of the optical lens satisfy: R3 / f < -5.5. Satisfying the above range can effectively control the surface curvature of the side surface of the second lens, smoothly receive the light emitted from the first lens, which is beneficial to reduce the front diameter of the lens and make the light transition smoothly in the lens; it can also reduce the generation of aberrations and improve the imaging quality of the optical lens.

[0071] In some embodiments, the radius of curvature R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: R5 / f < -0.5. Meeting this range allows for the reception and convergence of forward light rays. Light rays in the edge field of view will have a shorter optical path after passing through the third lens than those in the center field of view, thus altering the light trajectory of the edge field of view. This is beneficial for correcting edge field of view aberrations and improving the imaging quality of the optical lens.

[0072] In some embodiments, the radius of curvature R12 of the image-side surface of the sixth lens and the effective focal length f of the optical lens satisfy: R12 / f < -1.0. Satisfying this range causes the edge field rays to converge after passing through the image-side surface of the sixth lens, lowering the position of the light rays incident on the subsequent lens, reducing the rear aperture, and achieving miniaturization.

[0073] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 1.1 < (R1 - R2) / (R1 + R2). Satisfying the above range can effectively control the surface curvature of the object side surface of the first lens, increase the field angle while controlling the front aperture of the optical lens, and is also beneficial to the total length of the optical lens.

[0074] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: 0.5 < (R3 - R4) / (R3 + R4) < 0.7. Satisfying the above range can effectively control the surface curvature of the object side surface of the second lens, converge the light rays passing through the second lens, is beneficial to reducing the front aperture, and can also reduce the incident height of large-angle light rays, thereby reducing the rear aperture of the lens and the total length of the optical lens.

[0075] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: -0.6 < (R5 - R6) / (R5 + R6) < -0.3. Satisfying the above range can reduce the requirement for the distance of the incident light rays from the optical axis for the third lens, is beneficial to reducing the front aperture of the lens, and enables the light rays to transition smoothly in the lens.

[0076] In some embodiments, the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: -0.8 < (R13 - R14) / (R13 + R14) < -0.1. Satisfying the above range can receive as much light rays emitted by the sixth lens as possible, while increasing the imaging surface and improving the imaging quality of the optical lens.

[0077] In some embodiments, the sagittal height Sag3 of the clear aperture semi-diameter of the object side surface of the second lens and the clear aperture semi-diameter d3 of the object side surface of the second lens satisfy: -0.15 < Sag3 / d3 < -0.10. Satisfying the above range is beneficial to controlling the smaller included angle of the object side surface of the second lens, being able to highlight the detailed information of the central field of the optical lens, and improving the imaging quality of the optical lens.

[0078] In some embodiments, the sagittal height Sag4 of the clear aperture semi-diameter of the image side surface of the second lens and the clear aperture semi-diameter d4 of the image side surface of the second lens satisfy: -0.25 < Sag4 / d4 < -0.15. Satisfying the above range can make the object side surface and the image side surface of the second lens adopt a structure of approximately concentric circles, which can optimize the field curvature and improve the imaging quality of the optical lens.

[0079] In some embodiments, the sagittal height Sag5 of the clear aperture semi-diameter on the object side of the third lens and the clear aperture semi-diameter d5 of the object side of the third lens satisfy: -0.25 < Sag5 / d5 < -0.20. Meeting the above range can make the image side of the second lens and the object side of the third lens adopt a structure of approximate concentric circles, which can reduce the ghost reflection energy and improve the imaging quality of the optical lens.

[0080] In some embodiments, the sagittal height Sag12 of the clear aperture semi-diameter on the image side of the sixth lens and the clear aperture semi-diameter d12 of the image side of the sixth lens satisfy: -0.25 < Sag12 / d12 < -0.03. Meeting the above range can enable the sixth lens to effectively correct the off-axis aberration and improve the imaging quality.

[0081] In some embodiments, the sum ∑CT of the central thicknesses of each of the first lens to the seventh lens and the total optical length TTL of the optical lens satisfy: 0.60 < ∑CT / TTL < 0.70. Meeting the above range is beneficial to compressing the total length and volume of the optical lens and maintaining the miniaturization of the optical lens.

[0082] As an embodiment, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can be made of all-plastic lenses, or can be a combination of glass and plastic. Both can achieve good imaging effects. In this application, in order to further reduce the production cost and improve the imaging quality, a structure of seven all-plastic lenses is adopted.

[0083] As an embodiment, at least one of the object side or the image side of the first lens, the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens is an aspherical surface. The characteristics of an aspherical lens are that the curvature changes continuously from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality.

[0084] To make the system have better optical performance, multiple aspherical lenses are used in the lens, and the shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0085]

[0086] where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and A, B, C, D, E, F, G are the coefficients of the second-order, fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, and fourteenth-order curved surfaces respectively.

[0087] 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.

[0088] Example 1

[0089] Please see Figure 1 The diagram shows a schematic of the structure of an optical lens provided in Embodiment 1 of the present invention. The optical lens includes, along the optical axis from the object side to the imaging plane S17, the following components in sequence: 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 seventh lens L7, and a filter G1.

[0090] Among them, the first lens L1 is a plastic aspherical lens with negative optical power, its object-side surface S1 is concave, and its image-side surface S2 is concave; the second lens L2 is a plastic aspherical lens with positive optical power, its object-side surface S3 is concave, and its image-side surface S4 is convex; the third lens L3 is a plastic aspherical lens with negative optical power, its object-side surface S5 is concave, and its image-side surface S6 is convex; the fourth lens L4 is a plastic aspherical lens with positive optical power, its object-side surface S7 is convex, and its image-side surface S8 is convex; the fifth lens L5... The first lens is a plastic aspherical lens with negative optical power, its object side S9 is convex and its image side is concave; the sixth lens L6 is a plastic aspherical lens with positive optical power, its object side is convex and its image side S11 is convex, and the fifth lens L5 and the sixth lens L6 are cemented together to form a cemented lens, the cementing surface of which is S10; the seventh lens L7 is a plastic aspherical lens with negative optical power, its object side S12 is concave and its image side S13 is convex; the filter G1 has object side S14 and image side S15 both being flat.

[0091] The relevant parameters of each lens in the optical lens of Example 1 are shown in Table 1-1.

[0092] Table 1-1

[0093]

[0094] The surface coefficients of the aspherical lens in the optical lens of Example 1 are shown in Table 1-2.

[0095] Table 1-2

[0096]

[0097]

[0098] 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 ±0.15 mm, indicating that the optical lens can effectively correct the field curvature.

[0099] Figure 3 The relative illumination curve of Example 1 is shown, which represents the relative illumination value at different field-of-view angles on the imaging plane. The horizontal axis represents the half-field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 70% at the maximum half-field angle, indicating that the optical lens has excellent relative illumination.

[0100] Figure 4 The modulation transfer function (MTF) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this example is above 0.3 throughout the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases smoothly and evenly 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.

[0101] Example 2

[0102] Please see Figure 5 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 2 of the present invention. The structure of the optical lens in this embodiment is roughly the same as that of the optical lens in Embodiment 1 above. The main difference is that the fifth lens and the sixth lens are cemented lenses, and the curvature radius, aspherical coefficient, thickness and other properties of each lens surface are different.

[0103] The relevant parameters of each lens in the optical lens of Example 2 are shown in Table 2-1.

[0104] Table 2-1

[0105]

[0106] The surface coefficients of the aspherical lens in the optical lens of Example 2 are shown in Table 2-2.

[0107] Table 2-2

[0108]

[0109]

[0110] Figures 6 to 8 The field curvature curve, relative illumination curve, and modulation transfer function (MTF) curve of Example 2 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within ±0.1 mm, indicating that the optical lens can effectively correct field curvature. At the maximum half-field angle, the relative illumination value of the optical lens is still greater than 60%, indicating that the optical lens has good relative illumination. The MTF value of the optical lens is above 0.3 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0111] Example 3

[0112] Please see Figure 9 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 3 of the present invention. The structure of the optical lens in this embodiment is roughly the same as that of the optical lens in Embodiment 1 above. The main difference is that the fifth lens and the sixth lens are cemented lenses, and the curvature radius, aspherical coefficient, thickness and other properties of each lens surface are different.

[0113] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0114] Table 3-1

[0115]

[0116]

[0117] The surface coefficients of the aspherical lens in Example 3 are shown in Table 3-2.

[0118] Table 3-2

[0119] Face number K A B C S1 9.97E+01 0.00E+00 1.16E-03 -1.64E-04 S2 -2.74E+00 0.00E+00 4.67E-03 6.40E-04 S3 -6.33E+01 0.00E+00 -1.26E-02 7.37E-04 S4 3.10E+00 0.00E+00 1.67E-02 -1.43E-02 S5 -8.68E+00 0.00E+00 -1.24E-02 2.66E-03 S6 -1.41E+02 0.00E+00 -2.09E-02 1.17E-02 S7 1.38E+00 0.00E+00 -6.68E-02 -3.53E-04 S8 -4.73E+00 0.00E+00 -1.84E-02 1.75E-03 S9 -7.10E+01 0.00E+00 5.68E-03 -8.41E-04 S10 3.19E-02 0.00E+00 2.49E-02 -6.76E-03 S11 -3.54E+00 0.00E+00 -5.26E-03 1.06E-03 S12 -2.81E+00 0.00E+00 -3.33E-02 4.85E-03 S13 -9.18E+01 0.00E+00 -2.31E-02 1.61E-03 Face number D E F G S1 4.03E-06 1.17E-06 -7.24E-08 S2 -2.60E-04 5.16E-05 -2.53E-06 S3 -5.83E-04 1.99E-04 -1.82E-05 S4 1.24E-02 -3.56E-03 4.22E-04 S5 5.38E-03 -1.96E-03 7.74E-05 S6 1.11E-04 -8.94E-04 -4.90E-04 S7 -6.12E-03 2.41E-03 -1.35E-03 S8 -3.71E-03 1.18E-03 -3.29E-04 S9 6.58E-04 -4.38E-05 -1.60E-06 S10 1.19E-03 3.17E-04 -4.97E-05 S11 2.81E-04 5.27E-05 -6.68E-06 S12 -2.82E-04 3.82E-05 -1.37E-05 8.79E-07 S13 -2.65E-04 4.74E-05 -3.36E-06 -2.30E-08

[0120] Figures 10 to 12 The field curvature curve, relative illumination curve, and modulation transfer function (MTF) curve of Example 3 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within ±0.3 mm, indicating that the optical lens can effectively correct field curvature. At the maximum half-field angle, the relative illumination value of the optical lens is still greater than 60%, indicating that the optical lens has good relative illumination. The MTF value of the optical lens is above 0.3 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0121] Please refer to Table 4, which shows the optical characteristics corresponding to the three embodiments above, including the effective focal length f of the optical lens, the maximum field of view FOV, the entrance pupil diameter EPD, the total optical length TTL, the aperture value FNO, the image height IH corresponding to the maximum field of view, the incident angle CRA of the principal ray on the image plane at the maximum field of view, and the values ​​corresponding to each conditional expression in each embodiment.

[0122] Table 4

[0123]

[0124]

[0125] In summary, the optical lens in this embodiment of the invention, by reasonably allocating the optical power of each lens, reasonably matching the surface shape of each lens, and reasonably setting the thickness of each lens and the spacing between each lens, and by adopting a seven-piece plastic aspherical lens structure, can achieve a large field of view (maximum FOV value of 178°), a large aperture (minimum FNO value of 2.0), miniaturization (minimum TTL value of 10.53mm), and high pixel count, thereby meeting the imaging requirements of automotive lenses.

[0126] 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.

[0127] 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, comprising seven lenses in sequence from an object side to an image plane along an optical axis, wherein: a first lens with negative refractive power, an object side surface of which is concave and an image side surface of which is concave; a second lens with positive refractive power, an object side surface of which is concave and an image side surface of which is convex; a third lens with negative refractive power, an object side surface of which is concave and an image side surface of which is convex; a fourth lens with positive refractive power, an object side surface of which is convex and an image side surface of which is convex; a fifth lens with negative refractive power, an image side surface of which is concave; a sixth lens with positive refractive power, an object side surface of which is convex and an image side surface of which is convex; and a seventh lens with negative refractive power, an object side surface of which is concave and an image side surface of which is convex; a radius of curvature R1 of the object side surface of the first lens and a radius of curvature R2 of the image side surface of the first lens satisfy: 1.1 < (R1-R2) / (R1+R2) ≤ 1.12; a radius of curvature R13 of the object side surface of the seventh lens and a radius of curvature R14 of the image side surface of the seventh lens satisfy: -0.8 < (R13-R14) / (R13+R14) < -0.1; and an effective focal length f of the optical lens, a maximum field of view FOV of the optical lens and an image height IH corresponding to the maximum field of view of the optical lens satisfy: 91.08° ≤ f*FOV / IH < 100.0°. An optical total length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 3.56 ≤ TTL / f < 4.

0. The optical total length TTL of the optical lens and the image height IH corresponding to the maximum field of view of the optical lens satisfy: 1.83 ≤ TTL / IH < 2.

3. The radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 1.11 ≤ (R1-R2) / (R1+R2) ≤ 1.

12. The radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: -0.66 ≤ (R13-R14) / (R13+R14) ≤ -0.

15. The effective focal length f of the optical lens, the maximum field of view FOV of the optical lens and the image height IH corresponding to the maximum field of view of the optical lens satisfy: 91.08° ≤ f*FOV / IH ≤ 97.81°. An object side surface entrance pupil diameter D1 of the first lens and the image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.9 < D1 / IH < 1.

2. A radius of curvature R3 of the object side surface of the second lens and a radius of curvature R4 of the image side surface of the second lens satisfy: 0.5 < (R3-R4) / (R3+R4) < 0.

7. wherein A radius of curvature R5 of the object side surface of the third lens and a radius of curvature R6 of the image side surface of the third lens satisfy: -0.6 < (R5-R6) / (R5+R6) < -0.

3. An object side surface half entrance pupil radius sag3 of the second lens and an object side surface half entrance pupil d3 of the second lens satisfy: -0.15 < sag3 / d3 < -0.

10. ​ 2. The optical lens of claim 1, wherein, ​ 3. The optical lens of claim 1, wherein, ​ 4. The optical lens of claim 1, wherein, ​ ​ ​ 5. The optical lens of claim 1, wherein, ​ 6. The optical lens of claim 1, wherein, ​ 7. The optical lens of claim 1, wherein, ​ 8. The optical lens of claim 1, wherein, ​ 9. The optical lens of claim 1, wherein, An image-side surface sagittal half-aperture radius Sag12 of the sixth lens satisfies -0.25 < Sag12 / d12 < -0.

03.

10. The optical lens of claim 1, wherein, A sum ∑CT of central thicknesses of the first lens to the seventh lens satisfies 0.60 < ∑CT / TTL < 0.70.

Images