Optical lens

Abstract

The present invention provides an optical lens, the number of lenses with optical power is four, and successively includes, along the optical axis from the object side to the imaging surface: a first lens with positive optical power, its object side is convex, and its image side is concave; a second lens with positive optical power, its object side is convex; a third lens with positive optical power, its object side is concave, and its 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 optical lens provided by the present invention has one or more advantages such as miniaturization, high pixels, small distortion, large aperture, and high imaging quality through specific surface shape matching and reasonable optical power distribution.

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 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 has four lenses with optical power, which are arranged sequentially along the optical axis from the object side to the imaging plane: The first lens with positive optical power has a convex object side and a concave image side. A second lens with positive optical power has a convex object-side surface; A third lens with positive optical power has a concave object side and a convex image side. 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 clear aperture CSD11 of the object side surface of the first lens and the clear aperture CSD41 of the object side surface of the fourth lens satisfy: 0.2 < CSD11 / CSD41 < 0.6.

[0010] Further 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] Further 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] Further preferably, the focal length f2 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] Further 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 matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, achieve the balance of miniaturization and high pixels, and make the lens 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, where: Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

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

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

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

[0019] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 6 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0039] Figure 25 This 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 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.

[0047] 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.

[0048] The optical lens provided in this embodiment of the invention has four lenses with optical power, which are arranged sequentially from the object side to the imaging plane along the optical axis as a first lens, a second lens, a third lens, and a fourth lens.

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

[0050] In some embodiments, the optical lens may also include an aperture stop, which may be located between the object side and the first lens. It is understood that the aperture stop is used to limit the amount of light entering the lens, thereby altering the brightness of the image.

[0051] In some embodiments, the optical lens may further include a filter, which may be disposed between the fourth lens and the imaging surface. The filter is used to filter out interfering light and prevent 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 view 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 of view, it is possible to effectively shorten the total optical length of the optical lens while ensuring that the optical lens has high pixels, 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 view 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 and 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 of view, 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 a large image plane characteristic, 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 of view 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 view of the optical lens and increase the aperture of the optical lens, realizing the characteristics of a large field angle of view and a large aperture. The realization of the large field angle of view 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 rapid decrease in the relative brightness of the edge field of view caused by the large field angle of view, 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 beneficial for making the captured image clearer; at the same time, a short focal length combined with a large aperture enables the optical lens to have a large field angle of view to capture more scene information, and at the same time solves the problem of low-light shooting through the large aperture, and strengthens the sense of hierarchy of the picture with flexible depth-of-field control.

[0056] In some embodiments, 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. 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 surface of the second lens and the object side surface of the third lens within a reasonable range, shorten the overall optical length of the optical lens, achieve the miniaturized design of the optical lens, and is also beneficial to avoid interference between the second lens and the third lens due to too small distance between them, and at the same time avoid the second lens and the third lens being too curved, reducing the process difficulty and defective risk of the optical lens.

[0057] In some embodiments, the clear aperture radius CSD11 of the object side surface of the first lens and the clear aperture radius CSD41 of the object side surface of the fourth lens satisfy: 0.2 < CSD11 / CSD41 < 0.6. By satisfying the above conditional formula and controlling the ratio of the clear aperture radius of the object side end of the first lens to the clear aperture radius of the object side end of the fourth lens, the optical lens can have a smaller aperture size to meet the small head design; at the same time, it ensures that the optical lens can achieve large-angle light collection, realize large-field-angle 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 radius CSD11 of the object side surface of the first lens and the clear aperture radius 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 caused by too wide light beam on the second lens, 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 overall 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 restricted, which is beneficial to reducing the bending degree of the 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, making the astigmatism not too large while the optical lens has 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 achieve reasonable deflection of the light rays from the marginal field of view of the first lens, prevent excessive deflection of the light rays, thereby correcting the marginal aberration of the optical lens and improving 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. By satisfying the above conditional formula, the shape of the object side surface of the second lens near the optical axis is convex, so that the light rays passing through the first lens are contracted into the second lens, which can reduce the size of the subsequent lens, contribute to the miniaturization of the optical lens, and the second lens can effectively reduce 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. By satisfying the above conditional formula, the optical power of the third lens can be effectively regulated to achieve reasonable deflection of the light rays from the marginal field of view of the first lens and the second lens, prevent excessive deflection of the light rays, thereby correcting the marginal aberration of the optical lens and improving the imaging resolution; and can share the optical power burden of the second lens, so that the optical power of the second lens does not need to be too strong, thereby facilitating reducing the aberration influence 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. By satisfying the above conditional formula, the object side surface of the third lens is concave, which cancels the spherical aberration brought by the first two positive optical power lenses, and at the same time reduces the incident angle of the off-axis light rays, significantly improving astigmatism and coma, and greatly improving the clarity of the picture 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. By satisfying the above conditional formula, the incident light rays at different field angles of the optical lens can all 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. By satisfying the above conditional formula, by controlling the ratio of the effective focal length of the optical lens to the entrance pupil diameter, it helps to improve the light receiving ability of the optical lens, obtain as much object-side information as possible, and thus obtain imaging information with higher brightness and resolution.

[0067] In some embodiments, the central thickness CT2 of the second lens 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 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 further beneficial to improving the imaging quality of the optical lens.

[0068] In some embodiments, the clear aperture semi-diameter CSD31 of the object side surface of the third lens and the sagittal height SAG31 of the clear aperture semi-diameter 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, and at the same time it can 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 can further converge the light from the first three lenses, correct the aberration problems brought by the first three lenses, and can 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 view 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 principal 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 view of the optical lens. By satisfying the above conditional formula, the optical lens has at least one or more advantages such as 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, production costs can be effectively reduced. Conversely, when the lens material is glass, the low dispersion characteristic of glass itself can effectively correct the geometric chromatic aberration of the optical system. That is, the first, second, third, and fourth lenses of the present invention can all be made of plastic or all of glass; alternatively, some lenses can be made of plastic, while the remaining lenses are made of glass.

[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 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. Example 1

[0075] Please see Figure 1 The figure shown is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, in sequence along the optical axis from the object side to the imaging plane: aperture ST, first lens L1, second lens L2, third lens L3, fourth lens L4, and filter G1.

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

[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 respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0081] Figure 2 The astigmatism curve of Example 1 is shown, 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 The F~Tan (Theta) distortion curve of Example 1 is shown, which represents 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 4The diagram shows the axial aberration curves for Example 1, representing the aberrations of each wavelength along the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. The diagram shows that the axial aberration offset is controlled within ±0.1 mm, indicating that the optical lens can effectively correct axial aberrations.

[0084] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.940 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 diagram, 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 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 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.

[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 respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0089] from Figure 7 As can be seen, 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] from Figure 8As can be seen, 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] from Figure 9 As can be seen, the axial aberration offset is controlled within -0.05mm to 0.15mm, indicating that the optical lens can effectively correct axial aberration.

[0092] from Figure 10 As can be seen, 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 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.

[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 respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0097] from Figure 12 As can be seen, 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] from Figure 13 As can be seen, 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] from Figure 14As can be seen, the axial aberration offset is controlled within -0.15mm to 0.05mm, indicating that the optical lens can effectively correct axial aberration.

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

[0101] Please see Figure 16 The figure shown is 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 respectively as follows: Figure 17 , Figure 18 , Figure 19 , Figure 20 As shown.

[0105] from Figure 17 As can be seen, 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] from Figure 18 As can be seen, 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] from Figure 19 As can be seen, the axial aberration offset is controlled within -0.1mm to 0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0108] from Figure 20As can be seen, 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 see Figure 21 The figure 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 a convex surface; the object-side surface S7 of the fourth lens L4 is a concave surface; the image-side surface S8 of the fourth lens L4 is a convex surface; 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 respectively as follows: Figure 22 , Figure 23 , Figure 24 , Figure 25 As shown.

[0113] from Figure 22 As can be seen, 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] from Figure 23 As can be seen, 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] from Figure 24 As can be seen, the axial aberration offset is controlled within ±0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0116] from Figure 25 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3μm to 2μm, indicating that the optical lens 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, It sequentially includes from the object side to the imaging plane along the optical axis: 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°; 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.

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 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, and the effective focal length f of the optical lens satisfies: 2.4mm < f < 2.8mm.

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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