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 optical power, its object side being convex and its image side being concave; a second lens with negative optical power, its object side being concave; a third lens with positive optical power, its object side being convex and its image side being convex; a fourth lens with positive optical power, its object side being convex and its image side being concave; a fifth lens with positive optical power, its object side being convex near the optical axis and its image side being convex; a sixth lens with negative optical power, its object side being concave; and a seventh lens with negative optical power, its object side being convex near the optical axis and its image side being concave near the optical axis. The optical lens provided by this invention, through a specific combination of surface shapes and a reasonable allocation of optical power, enables the lens to possess one or more advantages such as a large field of view, a large aperture, a large image height, high pixel count, and high image quality.

Description

Technical Field

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

[0002] With the widespread adoption of remote work and online education, video conferencing has become an indispensable part of people's daily lives and work. The quality of video conferencing largely depends on the optical lens used, which places higher demands on these lenses. For example, to provide clear video quality, video conferencing lenses typically need to offer high resolution, such as 1080p or 4K; and to effectively capture participants in the meeting room, they often require a wider shooting range. Traditional video conferencing lenses have limitations to varying degrees, such as low resolution, small shooting range, and poor imaging performance in low-light or dimly lit environments. Therefore, there is an urgent need for an optical lens that can meet the needs of video conferencing. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0004] This invention provides an optical lens comprising seven lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0005] The first lens with negative optical power has a convex object side and a concave image side.

[0006] A second lens with negative optical power has a concave object side.

[0007] A third lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0008] The fourth lens with positive optical power has a convex object side and a concave image side.

[0009] The fifth lens with positive optical power has an object-side surface that is convex near the optical axis and an image-side surface that is convex.

[0010] The sixth lens has negative optical power and its object side is concave.

[0011] The seventh lens with negative optical power has an object-side surface that is convex near the optical axis and an image-side surface that is concave near the optical axis.

[0012] Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4 <TTL / f<4.8。

[0013] 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: 49° < (f × FOV) / IH < 60°.

[0014] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.1 < f1 / f < -1.7.

[0015] Further preferably, the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -1.4 < (R11 + R12) / (R11 - R12) < -0.2.

[0016] Further preferably, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.1 < f1 / f7 < 0.65.

[0017] Further preferably, the true image height IH corresponding to the maximum field angle of the optical lens and the aperture value Fno of the optical lens satisfy: 4 mm < IH / Fno < 4.3 mm.

[0018] Further preferably, the vertical distance YC71 between the anastigmatism point on the object side surface of the seventh lens and the optical axis and the clear aperture semi-diameter DM71 of the object side surface of the seventh lens satisfy: 0.15 < YC71 / DM71 < 0.3; the vertical distance YC72 between the anastigmatism point on the image side surface of the seventh lens and the optical axis and the clear aperture semi-diameter DM72 of the image side surface of the seventh lens satisfy: 0.55 < YC72 / DM72 < 0.6.

[0019] Further preferably, the sagittal height SAG71 of the clear aperture semi-diameter of the object side surface of the seventh lens, the sagittal height SAG72 of the clear aperture semi-diameter of the image side surface of the seventh lens, and the central thickness CT7 of the seventh lens satisfy: -0.4 < (SAG72 - SAG71) / CT7 < 0.2.

[0020] 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: 7 < IH / EPD < 9.

[0021] Further preferably, the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1 < R14 / f < 1.2.

[0022] Compared with existing technologies, the optical lens provided by this invention uses seven lenses with specific optical power. Through specific surface shape matching 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, giving the lens one or more advantages such as a large field of view, large aperture, large image height, high pixel count, and high imaging quality. Attached Figure Description

[0023] 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:

[0024] Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0025] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 3 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 4 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 5 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 6 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0030] Figure 7 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 8 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 9 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 10 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 11 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 12 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 13 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 14 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 15 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0039] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] The optical lens provided in this embodiment of the invention comprises seven lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane as follows: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0048] In some embodiments, the first lens may have negative optical power, with a convex object-side surface and a concave image-side surface. The second lens may have negative optical power, with a concave object-side surface and an image-side surface that may be either concave or convex. The third lens may have positive optical power, with a convex object-side surface and an convex image-side surface. The fourth lens may have positive optical power, with a convex object-side surface and a concave image-side surface. The fifth lens may have positive optical power, with a convex object-side surface near the optical axis and an convex image-side surface. The sixth lens may have negative optical power, with a concave object-side surface and an image-side surface that may be either concave or convex. The seventh lens may have negative optical power, with a convex object-side surface near the optical axis and an concave image-side surface near the optical axis.

[0049] In some embodiments, the optical lens may also include an aperture stop, which may be located between the fourth and fifth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens to change the brightness of the image. When the aperture stop is located between the fourth and fifth lenses, it facilitates the correction of aperture aberrations.

[0050] In some embodiments, the optical lens may further include a filter disposed between the seventh lens and the imaging surface. The filter is used to filter out interfering light and prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0051] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4 < TTL / f < 4.8. Satisfying the above conditions can effectively limit the length of the lens and is conducive to the miniaturization of the optical lens.

[0052] 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: 49° < (f × FOV) / IH < 60°. Satisfying the above conditional formula, by reasonably restricting the relationship between the focal length, field angle, and image height of the optical lens, it is conducive to achieving the balance of a large field angle and large target surface imaging of the optical lens, and better meeting the usage requirements of video conferencing cameras.

[0053] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.1 < f1 / f < -1.7. Satisfying the above conditions, the first lens has an appropriate negative focal length, which is conducive to expanding the field angle of the optical lens.

[0054] In some embodiments, the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -1.4 < (R11 + R12) / (R11 - R12) < -0.2. Satisfying the above conditions, reasonably controlling the curvature radii of the object side surface and image side surface of the sixth lens near the optical axis is conducive to controlling the shape of the sixth lens, correcting the aberration generated by itself, and improving the imaging quality.

[0055] In some embodiments, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.1 < f1 / f7 < 0.65. Satisfying the above conditions, by reasonably setting the focal length relationship between the first and last lenses in the lens, while ensuring that as much light as possible enters the system, the area of light entering the imaging surface is increased, which is conducive to achieving large image surface imaging of the lens, while increasing the light input and improving the relative illuminance of the system.

[0056] [[ID=IS]]In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the aperture value Fno of the optical lens satisfy: 4 mm < IH / Fno < 4.3 mm. Satisfying the above conditions, while maintaining a large image surface of the optical lens, the balance between the aperture of the optical lens and the large image surface is achieved.

[0057] In some embodiments, the vertical distance YC71 between the inflection point on the object side surface of the seventh lens and the optical axis and the clear aperture semi-diameter DM71 of the object side surface of the seventh lens satisfy: 0.15 < YC71 / DM71 < 0.3; the vertical distance YC72 between the inflection point on the image side surface of the seventh lens and the optical axis and the clear aperture semi-diameter DM72 of the image side surface of the seventh lens satisfy: 0.55 < YC72 / DM72 < 0.6. Meeting the above ranges and reasonably controlling the positions of the inflection points on the object side and image side surfaces of the seventh lens helps to strengthen the aberration correction of the off-axis field and improve the imaging quality of the marginal field.

[0058] In some embodiments, the sagittal height SAG71 of the clear aperture semi-diameter of the object side surface of the seventh lens, the sagittal height SAG72 of the clear aperture semi-diameter of the image side surface of the seventh lens, and the central thickness CT7 of the seventh lens satisfy: -0.4 < (SAG72 - SAG71) / CT7 < 0.2. Meeting the above conditions and controlling the relationship between the difference in sagittal heights of the image side and object side surfaces of the seventh lens and the central thickness of the seventh lens is beneficial to correcting the coma of the off-axis field and improving the imaging quality of the off-axis field of the optical lens.

[0059] 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: 7 < IH / EPD < 9. Meeting the above ranges enables the optical lens to satisfy a large image plane while also ensuring sufficient image plane brightness in the marginal field, preventing vignetting, and thus improving the imaging quality.

[0060] In some embodiments, the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1 < R14 / f < 1.2. Meeting the above conditions is beneficial to alleviating the degree of light deflection through the lens and can effectively reduce aberrations.

[0061] 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: 2.7 < IH / f < 3.3. Meeting the above conditions can achieve a larger field angle and imaging range, and can achieve the characteristics of a large image plane while ensuring the depth of field of the optical lens, thus improving the imaging quality of the optical system.

[0062] 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: 1.3 < TTL / IH < 1.6. Meeting the above conditions can balance the relationship between the image height and the total length, achieve high-pixel imaging while also achieving a short total length, and can directly image vertically without relying on a prism to deflect light for imaging.

[0063] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -8 < f2 / f < -1.6. Meeting the above conditions, and the second lens also being a negative lens, can further diverge light and increase the field angle of the imaging system.

[0064] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1.2 < f3 / f < 1.5. Meeting the above conditions, the third lens converges the incident light at the front end, which is beneficial to correcting the aberration and distortion of the edge field caused by the front lens group, making the lens have less distortion and capable of providing a high-definition imaging effect.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.5 < f4 / f < 185. Meeting the above conditions, by reasonably setting the focal length of the fourth lens, it is beneficial to the smooth transition of light, facilitating the correction of astigmatism and field curvature, improving the imaging quality of the optical lens, and ensuring the stability of the optical system.

[0066] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 < f5 / f < 1.2. The fifth lens meeting the above conditions can further focus light, adjust the angle of the chief ray, optimize the imaging quality, and correct the remaining aberrations (such as distortion, chromatic aberration, etc.), reducing the distortion of the wide-angle lens.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.7 < f6 / f < -1.4. Meeting the above conditions, the sixth lens has an appropriate negative focal length, which is beneficial to further increasing the imaging area of the optical lens, while balancing various aberrations generated by the front lens group and improving the imaging quality of the optical lens.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -15 < f7 / f < -3. Meeting the above conditions, the seventh lens can extend the light convergence point to a higher imaging position, and the light divergence effect is better, further increasing the light transmission while ensuring high imaging quality.

[0069] 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 < 61°. Meeting the above conditions is beneficial to increasing the light input of the lens, enabling the lens to achieve high-definition imaging in a dim environment.

[0070] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.45 < BFL / f < 0.52. Meeting the above range is conducive to achieving a balance between obtaining good imaging quality and an optical back focal length that is easy to assemble. While ensuring the imaging quality of the optical lens, it avoids interference between the lens and other components and reduces the assembly process difficulty of the camera module.

[0071] 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: 4 < R1 / R2 < 4.5. Meeting the above conditions can reasonably set the surface shape of the first lens, enhance the light collection ability of the first lens, and thus achieve an ultra-large viewing angle.

[0072] In some embodiments, the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: -0.6 < R5 / R6 < -0.2. Meeting the above conditions, the third lens can balance the system field curvature and avoid deterioration of the edge image quality.

[0073] In some embodiments, the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -0.6 < R11 / R12 < 0.2. Meeting the above conditions, by reasonably setting the curvature radius of the sixth lens, the aberration of the optical lens can be corrected and the tolerance sensitivity of the optical lens can be reduced.

[0074] In some embodiments, the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 1.2 < R13 / R14 < 3.2. Meeting the above range, by reasonably limiting the surface shape of the seventh lens, it helps the light to accurately focus on the imaging plane and improves the clarity and brightness uniformity of the imaging.

[0075] In some embodiments, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: -2.4 < (R3 + R4) / (R3 - R4) < 0.5. Meeting the above range can make the light trend more stable; at the same time, it can correct coma and field curvature, improve the flatness of the imaging, and enhance the imaging quality of the optical lens.

[0076] In some embodiments, the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 1.9 < (R13 + R14) / (R13 - R14) < 8. Meeting the above range, by reasonably limiting the shapes of the object side surface and the image side surface of the seventh lens, it can control the seventh lens to have an appropriate surface shape, which helps to control the light trend of the edge field of view and improve the imaging quality of the edge field of view.

[0077] In some embodiments, the central thickness CT4 of the fourth lens and the central thickness CT5 of the fifth lens satisfy: 0.45 < CT4 / CT5 < 1. Meeting the above conditions enables a reasonable configuration of the ratio of the thickness of the fourth lens on the optical axis to the thickness of the fifth lens on the optical axis. The fourth lens and the fifth lens can regulate each other to maintain the characteristic of miniaturization of the optical system.

[0078] In some embodiments, the central thickness CT6 of the sixth lens and the central thickness CT7 of the seventh lens satisfy: 0.35 < CT6 / CT7 < 0.55. Meeting the above conditions can reduce the sensitivity of system performance, while ensuring the lens processing performance and assembly stability, and improving the assembly yield.

[0079] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis and the total optical length TTL of the optical lens satisfy: 0.45 < ∑CT / TTL < 0.6. Meeting the above conditions can effectively compress the total length of the optical lens.

[0080] In some embodiments, the distance CT56 between the fifth lens and the sixth lens on the optical axis and the central thickness CT5 of the fifth lens satisfy: 0.04 < CT56 / CT5 < 0.07. Meeting the above range is conducive to the structural design and production process of the optical lens while ensuring the imaging quality of the lens.

[0081] In some embodiments, the distance CT23 between the second lens and the third lens on the optical axis and the distance ET23 at the edges of the second lens and the third lens satisfy: 0.12 < CT23 / ET23 < 1.15. By making the optical system satisfy the above relational expression, while ensuring the assembly processability of the lens, the distance between the second lens and the third lens can be fully compressed, making the lens have the characteristic of miniaturization.

[0082] In some embodiments, the perpendicular distance YC72 between the anastigmatic point on the image side surface of the seventh lens and the optical axis and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.1 < YC72 / (IH / 2) < 0.12. Meeting the above conditional expression helps to strengthen the coma correction of the off-axis field and improve the imaging quality.

[0083] In some embodiments, the refractive index Nd3 of the third lens and the refractive index Nd2 of the second lens satisfy: 0.12 < Nd3 - Nd2 < 0.35. Meeting the above conditions can reasonably match the refractive indices of the second lens and the third lens, enabling the optical lens to meet the balance of a wide field of view and small chromatic aberration, which is beneficial to correcting the chromatic aberration of the optical lens.

[0084] In some embodiments, the sagittal height SAG61 of the clear aperture semi-diameter on the object side of the sixth lens, the sagittal height SAG62 of the clear aperture semi-diameter on the image side of the sixth lens, and the central thickness CT6 of the sixth lens satisfy: -1.2 < (SAG61 - SAG62) / CT6 < -0.6. By satisfying the above conditions, by controlling the relationship between the height difference of the sagittal heights of the image side and the object side of the sixth lens and the central thickness of the sixth lens, the shape of the sixth lens can be constrained, which is beneficial to the design and processing of the structure of the sixth lens, beneficial to correcting the aberrations of each field of view respectively, and beneficial to improving the imaging quality of the optical lens.

[0085] In some embodiments, the clear aperture semi-diameter DM11 on the object side of the first lens and the clear aperture semi-diameter DM72 on the image side of the seventh lens satisfy: 1.4 < DM11 / DM72 < 1.5. By satisfying the above conditions, while ensuring that light enters the system within a large range, the aperture size of the lens can be effectively reduced, which is beneficial to achieving the balance of the field of view and the aperture of the lens.

[0086] In some embodiments, the optical lens satisfies the conditional formula: 15 mm < TTL < 17 mm, 3.4 mm < f < 4 mm, 160° < FOV < 170°, 11 mm < IH < 12 mm, 2.65 < Fno < 2.75, 30° < CRA < 40°, where TTL represents the overall optical length of the optical lens, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, Fno represents the aperture value of the optical lens, and CRA represents the chief ray angle of incidence CRA at the maximum image height of the optical lens. By satisfying the above conditions, it shows that the optical lens provided by the embodiments of the present invention has at least one or more advantages such as a large image plane, a large field of view angle, miniaturization, etc.

[0087] In some embodiments, the seven lenses in the optical lens can all be made of plastic lenses or adopt a structure with a combination of glass and plastic materials. Preferably, the optical lens of the present invention adopts a lens structure with a combination of seven glass and plastic materials, which can improve the thermal stability performance. Specifically, the first lens and the third lens can be made of glass lenses, and the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all plastic lenses; adopting a glass-plastic hybrid structure can effectively reduce costs, correct aberrations, reduce the volume, and provide an optical lens product with higher cost performance.

[0088] In some embodiments, the first, second, third, fourth, fifth, sixth, and seventh lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, in the optical lens provided by this invention, the first and third lenses are spherical lenses, while the second, fourth, fifth, sixth, and seventh lenses can be aspherical lenses.

[0089] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations:

[0090]

[0091] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, and H are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0092] 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.

[0093] Example 1

[0094] 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 plane S17, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a filter G1.

[0095] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0096] The second lens L2 has negative optical power, its object side S3 is concave, and its image side S4 is concave.

[0097] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex.

[0098] The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side S8 is concave.

[0099] The fifth lens L5 has positive optical power, its object side S9 is convex near the optical axis, and its image side S10 is convex.

[0100] The sixth lens L6 has negative optical power, its object side S11 is concave, and its image side S12 is concave.

[0101] The seventh lens L7 has negative optical power. Its object-side surface S13 is convex near the optical axis, and its image-side surface S14 is concave near the optical axis.

[0102] The object-side surface S15 and the image-side surface S16 of filter G1 are both planar.

[0103] The imaging plane S17 is a plane.

[0104] The first lens L1 and the third lens L3 are glass spherical lenses; the second lens L2, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all plastic aspherical lenses.

[0105] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0106] Table 1-1

[0107]

[0108] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0109] Table 1-2

[0110]

[0111]

[0112] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0113] Figure 2The field curvature curve of the optical lens 100 in this embodiment is shown, which represents the degree of 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 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, indicating that the optical lens 100 can correct the field curvature well.

[0114] Figure 3 The diagram shows the axial aberration curve of the optical lens 100 in this embodiment, which represents the aberration of each wavelength on 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 figure, the axial aberration offset is controlled within ±0.05 mm, indicating that the optical lens 100 can correct axial aberration well.

[0115] Figure 4 The diagram shows the transverse chromatic aberration curve of the optical lens 100 in this embodiment. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.546 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 figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1 μm, indicating that the optical lens 100 can effectively correct chromatic aberration.

[0116] Figure 5 The MTF (Modulation Transfer Function) curve of the optical lens 100 in this embodiment is shown, which represents the lens imaging modulation at different spatial frequencies in various fields 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 embodiment is above 0.5 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, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0117] Example 2

[0118] Please see Figure 6 The figure shows 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 image-side surface S4 of the second lens L2 is convex; the image-side surface S12 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0119] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0120] Table 2-1

[0121]

[0122]

[0123] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0124] Table 2-2

[0125] Face number K B C D E F G H S3 7.47E-01 -1.26E-04 1.16E-04 -2.01E-05 2.02E-06 -1.36E-07 5.67E-09 -1.01E-10 S4 6.15E+01 3.64E-03 -3.46E-05 -2.64E-06 1.73E-06 -2.87E-08 -1.08E-08 8.79E-10 S7 1.15E+00 -1.41E-03 -9.25E-04 -1.38E-04 1.47E-05 -2.17E-06 -1.66E-06 1.82E-07 S8 2.95E+00 -1.01E-02 -3.22E-03 2.86E-04 -3.91E-04 -1.53E-04 2.30E-05 1.08E-06 S9 2.00E+02 -2.11E-03 5.61E-03 -1.15E-02 5.66E-03 9.25E-03 -1.42E-02 4.83E-03 S10 -1.01E+01 -8.29E-02 7.85E-03 -8.13E-04 -5.53E-05 -2.60E-03 1.76E-03 -4.16E-04 S11 -1.31E+01 -6.63E-02 -4.57E-03 6.03E-03 -4.08E-03 -5.70E-05 7.19E-04 -2.32E-04 S12 1.35E+01 -8.89E-03 2.27E-03 -1.67E-04 1.73E-05 -7.84E-06 2.10E-06 -1.94E-07 S13 -1.84E+01 -1.29E-02 1.01E-03 -4.90E-05 1.16E-06 -1.77E-08 3.38E-09 -1.33E-10 S14 -6.79E+00 -1.02E-02 9.63E-04 -8.47E-05 4.99E-06 -2.14E-07 6.00E-09 -9.40E-11

[0126] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0127] from Figure 7 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 the field curvature.

[0128] from Figure 8 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 200 can effectively correct axial aberration.

[0129] from Figure 9 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0130] from Figure 10 As can be seen, the MTF value of this embodiment is above 0.48 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.

[0131] Example 3

[0132] Please see Figure 11 The 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.

[0133] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0134] Table 3-1

[0135]

[0136] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0137] Table 3-2

[0138] Face number K B C D E F G H S3 6.78E+00 -2.39E-03 4.00E-04 -5.69E-05 5.67E-06 -3.36E-07 1.09E-08 -1.61E-10 S4 -7.98E+00 2.23E-03 2.12E-04 -4.04E-05 2.56E-07 7.83E-07 -8.51E-08 2.72E-09 S7 1.48E-01 -2.95E-03 3.03E-04 -4.26E-04 4.81E-05 -3.91E-06 -5.53E-07 5.81E-08 S8 4.92E+01 -6.47E-03 2.50E-03 -5.33E-03 3.81E-03 -1.73E-03 4.25E-04 -4.43E-05 S9 -2.00E+02 -1.28E-02 -5.84E-03 -4.19E-03 1.69E-03 -3.14E-03 1.82E-03 -6.77E-04 S10 -6.32E+00 -5.07E-02 -5.01E-04 1.59E-03 -1.62E-03 -9.68E-04 9.30E-04 -2.32E-04 S11 1.68E+00 -6.85E-03 -6.25E-03 3.90E-03 -1.72E-03 3.43E-04 5.60E-05 -1.92E-05 S12 -2.00E+02 -3.74E-03 2.05E-03 -5.63E-04 1.40E-04 -3.09E-05 6.62E-06 -6.85E-07 S13 -1.02E+02 -1.72E-02 8.46E-04 -1.87E-05 3.02E-06 -8.80E-08 -8.37E-09 3.10E-10 S14 -8.25E+00 -9.59E-03 7.83E-04 -6.35E-05 3.97E-06 -2.19E-07 8.37E-09 -1.50E-10

[0139] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0140] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.04mm, indicating that the optical lens 300 can effectively correct the field curvature.

[0141] from Figure 13 As can be seen, the axial aberration offset is controlled within ±0.03mm, indicating that the optical lens 300 can correct axial aberration well.

[0142] from Figure 14 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0143] from Figure 15 As can be seen, the MTF value of this embodiment is above 0.48 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] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0145] Table 4

[0146]

[0147]

[0148] In summary, the optical lens provided by the present invention adopts a seven-element glass-plastic hybrid structure. Through specific surface shape settings 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, giving the lens one or more advantages such as a large field of view, large aperture, large image height, high pixel count, and high imaging quality.

[0149] 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.

[0150] 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, characterized in that, Along the optical axis from the object side to the imaging plane, the following are included in sequence: The first lens with negative optical power has a convex object side and a concave image side. A second lens with negative optical power has a concave object side. A third lens with positive optical power has a convex object-side surface and a convex image-side surface. The fourth lens with positive optical power has a convex object side and a concave image side. The fifth lens with positive optical power has an object-side surface that is convex near the optical axis and an image-side surface that is convex. The sixth lens has negative optical power and its object side is concave. The seventh lens with negative optical power has an object-side surface that is convex near the optical axis and an image-side surface that is concave near the optical axis. Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4 <TTL / f<4.8; The radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1 <R14 / f<1.2。 2. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens, the maximum field of view FOV of the optical lens, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy the following condition: 49° < (f × FOV) / IH < 60°.

3. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.1 <f1 / f<-1.7。 4. The optical lens according to claim 1, characterized in that, The object-side radius of curvature R11 and the image-side radius of curvature R12 of the sixth lens satisfy the following condition: -1.4 < (R11 + R12) / (R11 - R12) < -0.

2.

5. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.1 <f1 / f7<0.65。 6. The optical lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field of view of the optical lens and the aperture value Fno of the optical lens satisfy: 4mm <IH / Fno<4.3mm。 7. The optical lens according to claim 1, characterized in that, The perpendicular distance YC71 between the inflection point on the object side of the seventh lens and the optical axis satisfies 0.15 with the half-aperture DM71 of the object side of the seventh lens. <YC71 / DM71<0.3; The perpendicular distance YC72 between the inflection point on the image side of the seventh lens and the optical axis satisfies the following condition with respect to the half-aperture DM72 of the image side of the seventh lens: 0.

55. <YC72 / DM72<0.6。 8. The optical lens according to claim 1, characterized in that, The object-side light-transmitting half-aperture height SAG71 of the seventh lens, the image-side light-transmitting half-aperture height SAG72 of the seventh lens, and the center thickness CT7 of the seventh lens satisfy the following condition: -0.4 < (SAG72 - SAG71) / CT7 < 0.

2.

9. The optical lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 7 <IH / EPD<9。 10. The optical lens according to claim 1, characterized in that, The object-side radius of curvature R11 and the image-side radius of curvature R12 of the sixth lens satisfy: -0.6 <R11 / R12<0.2。

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