Optical lens

Abstract

The invention provides an optical lens, which comprises four lenses with focal power, and sequentially comprises a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with positive focal power and a sixth lens with negative focal power from an object side to an imaging surface along an optical axis, the object side surface of the second lens is a convex surface; the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; the fourth lens has positive focal power; wherein the optical total length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens meet the following conditions: 0.7 lt; tTL / IHlt; and 0.9. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of miniaturization, high pixel, small distortion, large aperture, high imaging quality and the like.

Description

Optical lens Technical Field

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

[0002] With users' enthusiasm for thinner and lighter consumer electronics products (including mobile phones, computers, tablets, dashcams, etc.), and in pursuit of better imaging effects, optical lenses are required to meet both miniaturization and high pixel count. However, in the current technology, the optical lenses on the market cannot achieve a good balance between miniaturization and high pixel count, thus failing to meet users' photography experience. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide an optical lens that achieves miniaturization and high pixel balance, resulting in excellent image quality.

[0004] The technical solution adopted in this invention is as follows: an optical lens comprising four lenses with optical power, arranged sequentially along the optical axis from the object side to the imaging plane: a first lens with positive optical power, its object side being convex and its image side being concave; a second lens with positive optical power, its object side being convex; a third lens with positive optical power, its object side being concave and its image side being convex; and a fourth lens with positive optical power; wherein the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.7 <TTL / IH<0.9。

[0005] Further preferably, the true image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 1.6 <IH / f<1.9。

[0006] Further preferably, the maximum field of view (FOV) of the optical lens and the aperture value (Fno) of the optical lens satisfy: 33° <FOV / Fno<41°。

[0007] Further preferably, the effective focal length f of the optical lens and the aperture value Fno of the optical lens satisfy: 1mm <f / Fno<1.3mm。

[0008] Further preferably, the distance CT23 between the second lens and the third lens on the optical axis and the distance ET23 between the second lens and the third lens at the edge satisfy: 2 <CT23 / ET23<8。

[0009] Further preferably, the half-aperture CSD11 of the object-side surface of the first lens and the half-aperture CSD41 of the object-side surface of the fourth lens satisfy: 0.2 <CSD11 / CSD41<0.6。

[0010] More preferably, the clear aperture CSD11 of the object side surface of the first lens and the clear aperture CSD21 of the object side surface of the second lens satisfy: 0.75 < CSD11 / CSD21 < 0.95.

[0011] More preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1 < f1 / f < 1.7; the focal length f1 of the first lens, 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: 0.3 < f1 / (R1 + R2) < 1.2.

[0012] More preferably, the focal length f¬2 of the second lens and the effective focal length f of the optical lens satisfy: 3 < f2 / f < 201; the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.1 < R3 / f < 6.2.

[0013] More preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2 < f3 / f < 205; the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: -1.7 < R5 / f < -0.6.

[0014] The optical lens provided by the present invention adopts four lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and achieve the balance of miniaturization and high pixels, enabling the lens to have one or more advantages such as miniaturization, high pixels, small distortion, large aperture, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein: FIG. 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0016] FIG. 2 is an astigmatism curve diagram of the optical lens in Embodiment 1 of the present invention.

[0017] FIG. 3 is a F~Tan(Theta) distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

[0018] FIG. 4 is an axial aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0019] FIG. 5 is a lateral chromatic aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0020] FIG. 6 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0021] Figure 7 is an astigmatism curve of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 8 is a graph of F~Tan (Theta) distortion of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 9 is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 10 is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 11 is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0026] Figure 12 is an astigmatism curve of the optical lens in Embodiment 3 of the present invention.

[0027] Figure 13 is a graph of F~Tan (Theta) distortion of the optical lens in Embodiment 3 of the present invention.

[0028] Figure 14 is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 15 is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 16 is a schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0031] Figure 17 is an astigmatism curve of the optical lens in Embodiment 4 of the present invention.

[0032] Figure 18 is a graph showing the F~Tan (Theta) distortion curve of the optical lens in Embodiment 4 of the present invention.

[0033] Figure 19 is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0034] Figure 20 is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0035] Figure 21 is a schematic diagram of the optical lens in Embodiment 5 of the present invention.

[0036] Figure 22 is an astigmatism curve of the optical lens in Embodiment 5 of the present invention.

[0037] Figure 23 is a graph of F~Tan (Theta) distortion of the optical lens in Embodiment 5 of the present invention.

[0038] Figure 24 is an axial aberration curve of the optical lens in Embodiment 5 of the present invention.

[0039] Figure 25 is a chromatic aberration curve of the optical lens in Embodiment 5 of the present invention.

[0040] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0047] It should be noted that, without conflict, the embodiments and features in the embodiments of this application can be combined with each other. The following will describe this application in detail with reference to the drawings and in combination with the embodiments.

[0048] The optical lens provided by the embodiment of the present invention has four lenses with optical power, and they are, in order from the object side to the imaging surface along the optical axis, the first lens, the second lens, the third lens, and the fourth lens.

[0049] In some embodiments, the first lens may have a positive optical power, its object side is a convex surface, and its image side is a concave surface. The second lens may have a positive optical power, its object side is a convex surface, and its image side may be a concave surface or a convex surface. The third lens may have a positive optical power, its object side is a concave surface, and its image side is a convex surface. The fourth lens may have a positive optical power, its object side may be a concave surface or a convex surface, and its image side may be a concave surface or a convex surface.

[0050] In some embodiments, the optical lens may further include an aperture, and the aperture may be located between the object side and the first lens. It can be understood that the aperture is used to limit the amount of incident light to change the brightness of the image.

[0051] In some embodiments, the optical lens may further include a filter, and the filter may be disposed between the fourth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0052] 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: 0.7 < TTL / IH < 0.9. By satisfying the above conditional formula and reasonably configuring the total optical length of the optical lens and the true image height corresponding to the maximum field angle, it is possible to effectively shorten the total optical length of the optical lens while ensuring that the optical lens has a high pixel count, so that the optical lens meets the requirements of miniaturization while having a high imaging quality.

[0053] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.6 < IH / f < 1.9. By satisfying the above conditional formula, controlling the ratio of the effective focal length to the image height of the optical lens, shortening the effective focal length can expand the field angle, enabling the optical lens to capture a wider object-side space, increasing the width of the light beam entering the optical lens, improving the brightness at the image plane of the optical lens and avoiding vignetting; at the same time, enabling the optical lens to have the characteristic of a large image plane, matching a large-image-plane chip to improve the resolution and ensuring the imaging quality of the optical lens.

[0054] In some embodiments, the maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 33° < FOV / Fno < 41°. By satisfying the above conditional formula, it is beneficial to expand the field angle of the optical lens and increase the aperture of the optical lens, realizing the characteristics of a large field angle and a large aperture. The realization of the large field angle characteristic is beneficial for the optical lens to obtain more scene information and meet the requirements of large-range detection. The realization of the large aperture characteristic is beneficial for improving the problem of the rapid decrease of the relative brightness of the edge field of view caused by the large field angle, and thus is also beneficial for obtaining more scene information.

[0055] In some embodiments, the effective focal length f of the optical lens and the f-number Fno of the optical lens satisfy: 1mm < f / Fno < 1.3mm. By satisfying the above conditional formula, it is beneficial for the optical lens to obtain the characteristic of a large aperture, enabling the optical lens to have sufficient light input, which is thus beneficial for making the captured image clearer; at the same time, the short focal length combined with the large aperture enables the optical lens to have a large field angle to capture more scene information, and at the same time solves the problem of shooting in low light through the large aperture, and strengthens the sense of hierarchy of the picture with flexible depth-of-field control.

[0056] In some embodiments, the on-axis spacing CT23 between the second lens and the third lens and the off-axis spacing ET23 between the second lens and the third lens satisfy: 2 < CT23 / ET23 < 8. When the above conditional formula is satisfied, it is beneficial to control the air gap between the second lens and the third lens, as well as the curvature radii of the image side of the second lens and the object side of the third lens within a reasonable range, shorten the overall optical length of the optical lens, realize the miniaturized design of the optical lens, and is also beneficial for avoiding interference between the second lens and the third lens due to too small distance between them, and at the same time avoiding excessive bending of the second lens and the third lens, reducing the process difficulty and defective risk of the optical lens.

[0057] In some embodiments, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the clear aperture semi-diameter CSD41 of the object side surface of the fourth lens satisfy: 0.2 < CSD11 / CSD41 < 0.6. By satisfying the above conditional formula, by controlling the ratio of the clear aperture semi-diameter of the object side end of the first lens and the clear aperture semi-diameter of the object side end of the fourth lens, the optical lens can have a smaller aperture size, meeting the small head design; at the same time, it ensures that the optical lens can achieve large-angle light collection, realize large field-of-view imaging of the optical lens, increase the imaging area of the optical lens, and improve the imaging quality.

[0058] In some embodiments, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the clear aperture semi-diameter CSD21 of the object side surface of the second lens satisfy: 0.75 < CSD11 / CSD21 < 0.95. By satisfying the above conditional formula, the light beam converges orderly from the first lens to the second lens, avoiding the problem of excessive incident angle of marginal rays on the second lens due to the overly wide light beam, reducing the generation of monochromatic aberrations such as spherical aberration and coma, and at the same time reducing the difficulty of chromatic aberration correction.

[0059] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1 < f1 / f < 1.7. By satisfying the above conditional formula, the first lens can better converge the light rays incident from the object space, so as to increase the field-of-view range of the optical lens and shorten the total length of the optical lens. On the other hand, it can prevent the first lens from generating excessive aberrations, so that the optical lens has good imaging quality.

[0060] In some embodiments, the focal length f1 of the first lens, the curvature radius R1 of the object side surface of the first lens, and the curvature radius R2 of the image side surface of the first lens satisfy: 0.3 < f1 / (R1 + R2) < 1.2. By satisfying the above conditional formula, the surface shapes of the object side surface and the image side surface of the first lens can be constrained, which is beneficial to reducing the bending degree of light rays at the image side surface of the first lens, reducing the astigmatism of the optical lens, so as to balance the astigmatism problem brought by the large field-of-view angle of the optical lens, so that the astigmatism of the optical lens is not too large while having a large field of view, and further ensuring that the optical lens has excellent imaging quality.

[0061] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 3 < f2 / f < 201. By satisfying the above conditional formula, the optical power of the second lens can be effectively regulated to reasonably deflect the light rays from the marginal field of view of the first lens, preventing the light rays from being deflected too much, so as to correct the marginal aberration of the optical lens and improve the imaging resolution.

[0062] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.1 < R3 / f < 6.2. Meeting the above conditional formula makes the shape of the object side surface of the second lens convex near the optical axis, enabling the light rays passing through the first lens to be converged into the second lens, which can reduce the size of the subsequent lenses, contribute to the miniaturization of the optical lens, and the second lens can effectively reduce the generation of spherical aberration and astigmatism to improve the imaging quality of the optical lens.

[0063] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2 < f3 / f < 205. Meeting the above conditional formula enables the optical power of the third lens to be effectively regulated to achieve reasonable deflection of the light rays in the marginal fields of view from the first lens and the second lens, preventing excessive deflection of the light rays, thereby correcting the marginal aberration of the optical lens and improving the imaging resolution; and it can share the burden of the optical power of the second lens, so that the optical power of the second lens does not need to be too strong, thus facilitating reducing the influence of the aberration brought by the second lens.

[0064] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: -1.7 < R5 / f < -0.6. Meeting the above conditional formula makes the object side surface of the third lens concave, offsetting the spherical aberration brought by the first two positive optical power lenses and simultaneously reducing the incident angle of the off-axis light rays, significantly improving astigmatism and coma, and greatly enhancing the clarity of the image edge.

[0065] In some embodiments, the maximum field of view FOV of the optical lens and the chief ray angle of incidence CRA at the maximum image height of the optical lens satisfy: 2 < FOV / CRA < 2.9. Meeting the above conditional formula enables the incident light rays at different field of view angles of the optical lens to enter the image sensor at appropriate angles, making the brightness of the four corners and the center of the image sensor more uniform, improving the photosensitive performance of the image sensor, and improving the imaging quality of the optical lens.

[0066] In some embodiments, the effective focal length f of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.9 < f / EPD < 2.3. Meeting the above conditional formula helps to improve the light receiving ability of the optical lens by controlling the ratio of the effective focal length to the entrance pupil diameter of the optical lens, obtaining as much object space information as possible, and thus obtaining imaging information with higher brightness and resolution.

[0067] In some embodiments, the central thickness CT2 and the edge thickness ET2 of the second lens satisfy: 0.5 < CT2 / ET2 < 1.8. By satisfying the above conditional formula, by controlling the central thickness and the edge thickness of the second lens within a certain range, it is also possible to effectively balance the aberration generated by the optical lens, and at the same time, it is beneficial to the field curvature adjustment in engineering production, and thus beneficial to improving the imaging quality of the optical lens.

[0068] In some embodiments, the clear aperture semi-diameter CSD31 and the sagittal height SAG31 of the object side surface of the third lens satisfy: -16 < CSD31 / SAG31 < -2.2. By satisfying the above conditional formula, by adjusting the surface shape of the edge region of the object side surface of the third lens, it is beneficial to diverge the marginal field light rays, and at the same time, it is possible to correct the off-axis aberration of the marginal field of the optical lens and improve the imaging quality of the optical lens.

[0069] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 4 < f4 / f < 390. By satisfying the above conditional formula, by setting the fourth lens to have a positive optical power, it is possible to further converge the light rays from the first three lenses, correct the aberration problems brought by the first three lenses, and effectively improve the aberration of the marginal field, and enhance the overall imaging quality of the optical lens.

[0070] In some embodiments, the optical lens satisfies the following conditional formula: 2.4 mm < f < 2.8 mm; 3.3 mm < TTL < 3.7 mm; 75° < FOV < 85°; 1 mm < EPD < 1.3 mm; 1.95 < Fno < 2.3; 28° < CRA < 41°; 4.4 mm < IH < 4.7 mm. In the above conditional formula, f represents the effective focal length of the optical lens, TTL represents the overall optical length of the optical lens, FOV represents the maximum field angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the main ray incident angle at the maximum image height of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. By satisfying the above conditional formula, the optical lens has at least one or more advantages of short focal length, miniaturization, large field angle, large entrance pupil diameter, large aperture, large image plane, low distortion, low sensitivity and high pixel characteristics.

[0071] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. On the other hand, when the lens material is glass, due to the low dispersion characteristic of the glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. That is, the first lens, the second lens, the third lens, and the fourth lens of the present invention can all adopt plastic materials or all adopt glass materials; or some lenses can adopt plastic materials and the remaining lenses can adopt glass materials.

[0072] In some embodiments, the first lens, second lens, third lens, and fourth lens can be spherical lenses or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce the aberrations of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving lens miniaturization. More specifically, the first lens, second lens, third lens, and fourth lens of the present invention are aspherical lenses.

[0073] 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: 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.

[0074] 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 differ; specific differences can be found in 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. Embodiment 1

[0075] Please refer to Figure 1, which shows a schematic diagram 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, the following components in sequence: aperture ST, first lens L1, second lens L2, third lens L3, fourth lens L4, and filter G1.

[0076] The first lens L1 has positive optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave near the optical axis; the second lens L2 has positive optical power, its object-side surface S3 is convex near the optical axis, and its image-side surface S4 is concave near the optical axis; the third lens L3 has positive optical power, its object-side surface S5 is concave, and its image-side surface S6 is convex; the fourth lens L4 has positive optical power, its object-side surface S7 is convex, and its image-side surface S8 is concave near the optical axis; the object-side surface S9 and image-side surface S10 of the filter G1 are both planar; and the imaging surface S11 is planar.

[0077] The first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are plastic aspherical lenses.

[0078] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0079] Table 1-1 The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0080] Table 1-2 In this embodiment, the astigmatism curve, F~Tan (Theta) distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 100 are shown in Figures 2, 3, 4, and 5, respectively.

[0081] Figure 2 shows the astigmatism curve of Example 1, which represents the astigmatism 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 astigmatism in the meridional and sagittal image planes is controlled within -0.1 mm to 0.15 mm, indicating that the optical lens can effectively correct astigmatism.

[0082] Figure 3 shows the F~Tan (Theta) distortion curves of Example 1, which represent the distortion at different field-of-view angles on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F~Tan (Theta) distortion of the optical lens is controlled within -1% to 2%, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image, indicating that the optical lens can correct distortion well.

[0083] Figure 4 shows the axial aberration curves of Example 1, which represent the aberrations 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 ±0.1 mm, indicating that the optical lens can effectively correct axial aberrations.

[0084] Figure 5 shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.940 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 -3 μm to 2 μm, indicating that the optical lens can effectively correct chromatic aberration. Example 2

[0085] Please refer to Figure 6, which 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 object side S7 of the fourth lens L4 is concave; the image side S8 of the fourth lens L4 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0086] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0087] Table 2-1 The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0088] Table 2-2 In this embodiment, the astigmatism curve, F~Tan (Theta) distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 200 are shown in Figures 7, 8, 9, and 10, respectively.

[0089] As can be seen from Figure 7, the astigmatism of the meridional and sagittal image planes is controlled within -0.15mm to 0.25mm, indicating that the optical lens can effectively correct astigmatism.

[0090] As can be seen from Figure 8, the F~Tan (Theta) distortion of the optical lens is controlled within -1% to 2%, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image, indicating that the optical lens can correct distortion well.

[0091] As can be seen from Figure 9, the axial aberration offset is controlled within -0.05mm to 0.15mm, indicating that the optical lens can effectively correct axial aberration.

[0092] As shown in Figure 10, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±3μm, indicating that the optical lens can effectively correct chromatic aberration. Example 3

[0093] Please refer to Figure 11, which shows 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.

[0094] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0095] Table 3-1 The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0096] Table 3-2 In this embodiment, the astigmatism curve, F~Tan (Theta) distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are shown in Figures 12, 13, 14, and 15, respectively.

[0097] As can be seen from Figure 12, the astigmatism of the meridional and sagittal image planes is controlled within -0.15mm to 0.1mm, indicating that the optical lens can effectively correct astigmatism.

[0098] As can be seen from Figure 13, the F~Tan (Theta) distortion of the optical lens is controlled within -1% to 2%, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image, indicating that the optical lens can correct distortion well.

[0099] As can be seen from Figure 14, the axial aberration offset is controlled within -0.15mm to 0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0100] As shown in Figure 15, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -4μm to 3μm, indicating that the optical lens can effectively correct chromatic aberration. Example 4

[0101] Please refer to Figure 16, which shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0102] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0103] Table 4-1 The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0104] Table 4-2 In this embodiment, the astigmatism curve, F~Tan (Theta) distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 400 are shown in Figures 17, 18, 19, and 20, respectively.

[0105] As can be seen from Figure 17, the astigmatism of the meridional and sagittal image planes is controlled within -0.1mm to 0.15mm, indicating that the optical lens can effectively correct astigmatism.

[0106] As can be seen from Figure 18, the F~Tan (Theta) distortion of the optical lens is controlled within 0 to 2%, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image, indicating that the optical lens can correct distortion well.

[0107] As can be seen from Figure 19, the axial aberration offset is controlled within -0.1mm to 0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0108] As can be seen from Figure 20, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±3μm, indicating that the optical lens can effectively correct chromatic aberration. Example 5

[0109] Please refer to Figure 21, which shows a schematic diagram of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the image-side surface S4 of the second lens L2 is convex; the object-side surface S7 of the fourth lens L4 is concave; the image-side surface S8 of the fourth lens L4 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0110] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0111] Table 5-1 The surface profile parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0112] Table 5-2 In this embodiment, the astigmatism curve, F~Tan (Theta) distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 500 are shown in Figures 22, 23, 24, and 25, respectively.

[0113] As can be seen from Figure 22, the astigmatism of the meridional and sagittal image planes is controlled within -0.2mm to 0.15mm, indicating that the optical lens can effectively correct astigmatism.

[0114] As can be seen from Figure 23, the F~Tan (Theta) distortion of the optical lens is controlled within -1% to 2%, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image, indicating that the optical lens can correct distortion well.

[0115] As can be seen from Figure 24, the axial aberration offset is controlled within ±0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0116] As can be seen from Figure 25, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3μm to 2μm, indicating that the optical lens can correct chromatic aberration well.

[0117] Please refer to Table 6 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, maximum field of view FOV, principal ray incident angle CRA at the maximum image height of the optical lens, and the values ​​corresponding to each conditional expression in each embodiment.

[0118] Table 6 In summary, the optical lens provided by the present invention employs four lenses with specific optical power. Through specific surface shape combinations 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. While meeting the requirements of high pixel count, the structure is more compact and the outer diameter of the head is smaller, achieving a good balance between miniaturization and high pixel count. This effectively enhances the user's photography experience, giving the lens one or more advantages such as miniaturization, high pixel count, low distortion, large aperture, and high imaging quality.

[0119] 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.

[0120] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens having four lenses with optical power, characterized in that, Along the optical axis from the object side to the imaging plane, it successively includes: a first lens with positive optical power, whose object side is convex and whose image side is concave; a second lens with positive optical power, whose object side is convex; a third lens with positive optical power, whose object side is concave and whose image side is convex; a fourth lens with positive optical power; wherein, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.7 < TTL / IH < 0.9; the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 33° < FOV / Fno < 41°.

2. The optical lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.6 < IH / f < 1.

9.

3. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter CSD31 of the object side of the third lens and the sagittal height SAG31 of the clear aperture of the object side of the third lens satisfy: -16 < CSD31 / SAG31 < -2.

2.

4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the aperture value Fno of the optical lens satisfy: 1mm < f / Fno < 1.3mm.

5. The optical lens according to claim 1, characterized in that, The distance CT23 between the second lens and the third lens on the optical axis and the distance ET23 between the second lens and the third lens at the edge satisfy: 2 < CT23 / ET23 < 8.

6. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter CSD11 of the object side of the first lens and the clear aperture semi-diameter CSD41 of the object side of the fourth lens satisfy: 0.2 < CSD11 / CSD41 < 0.

6.

7. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter CSD11 of the object side of the first lens and the clear aperture semi-diameter CSD21 of the object side of the second lens satisfy: 0.75 < CSD11 / CSD21 < 0.

95.

8. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1 < f1 / f < 1.7; the focal length f1 of the first lens, the curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: 0.3 < f1 / (R1 + R2) < 1.

2.

9. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 3 < f2 / f < 201; the curvature radius R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: 1.1 < R3 / f < 6.

2.

10. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2 < f3 / f < 205; the curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: -1.7 < R5 / f < -0.6.

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