Optical lens

Abstract

The application provides an optical lens, the number of lenses with optical power is four, and the optical lens comprises, in sequence from an object side to an imaging surface along an optical axis, a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power and a fourth lens with positive optical power, wherein the object side of the first lens is a convex surface, the image side of the first lens is a concave surface, the object side of the second lens is a convex surface, the image side of the second lens is a convex surface, the object side of the third lens is a convex surface, the image side of the third lens is a convex surface near the optical axis, and the object side of the fourth lens is a convex surface near the optical axis; wherein the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy 13.5 < TTL / f < 14.9. The optical lens provided by the application has one or more advantages such as a large field of view, a short total length, a large aperture, a large image surface and high imaging quality by 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 technological advancements, more and more science enthusiasts are researching large-screen or full-screen displays. Under-display fingerprint recognition has thus mutually promoted the development of large-screen or full-screen displays. The advantage of under-display fingerprint solutions lies in their ability to be "hidden" (completely concealed within the screen). Although there are various methods of under-display fingerprint recognition, due to the advantages of light—fast, stable, and transparent—optical under-display fingerprint lenses with large apertures, ultra-thin designs, and miniaturization are receiving more market attention and demand. Current wide-angle under-display fingerprint lenses do not offer a wide enough field of view, lack sufficient spatial depth in the captured images, suffer from unstable recognition, and have poor environmental adaptability. Summary of the Invention

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

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

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

[0006] A second lens with positive optical power has a convex object-side surface and a convex image-side surface;

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

[0008] The fourth lens with positive optical power has a convex object-side surface near the optical axis;

[0009] Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 13.5 <TTL / f<14.9。

[0010] Further preferably, the half-object height OBH of the optical lens and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 3.2 <OBH / IH<3.4。

[0011] Further preferably, the total optical length (TTL) of the optical lens and the aperture value (Fno) of the optical lens satisfy: 2.95mm. <TTL / Fno<3mm。

[0012] Further preferably, the maximum field of view (FOV) of the optical lens and the aperture value (Fno) of the optical lens satisfy: 103° <FOV / Fno<105°。

[0013] More preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2.3 < f1 / f < -2.1; 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: 54 < R1 / R2 < 92.

[0014] More preferably, the focal length f2 of the second lens, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 5.8 < (f2 + f3) / f < 6.3.

[0015] More preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 2.7 < f2 / f < 3.4; the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -3.5 < R4 / R3 < -2.6.

[0016] More preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 170 < f4 / f < 210.

[0017] More preferably, the combined focal length f34 of the third lens and the fourth lens and the effective focal length f of the optical lens satisfy: 2.8 < f34 / f < 3.2.

[0018] More preferably, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the distance CT12 between the first lens and the second lens on the optical axis satisfy: 1.55 < CSD11 / CT12 < 1.75.

[0019] Compared with the prior art, 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, the imaging quality of the optical lens can be improved, the aberration can be reduced, the imaging quality of the optical lens can be enhanced, and the lens has one or more advantages such as a large viewing angle, a short overall length, a large aperture, a large image plane, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0021] Figure 1 is a schematic diagram of the structure of the optical lens in Embodiment 1 of the present invention Figure 1 .

[0022] Figure 2 is a schematic diagram of the structure of the optical lens in Embodiment 1 of the present invention Figure 2 .

[0023] Figure 3 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0024] Figure 4 This is the F-Tan(θ) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0025] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 6 This is a relative illumination curve of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention. Figure 1 .

[0028] Figure 8 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention. Figure 2 .

[0029] Figure 9 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0030] Figure 10 This is the F-Tan(θ) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 11 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 12 This is a relative illumination curve of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 13 This is a schematic diagram of the optical lens structure in Embodiment 3 of the present invention. Figure 1 .

[0034] Figure 14 This is a schematic diagram of the optical lens structure in Embodiment 3 of the present invention. Figure 2 .

[0035] Figure 15 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 16 This is the F-Tan(θ) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 17 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 18 This is a relative illumination curve of the optical lens in Embodiment 3 of the present invention.

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

[0040] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0041] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0042] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0043] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0044] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0045] Unless otherwise 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.

[0046] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will detail this application by referring to the drawings and in combination with the embodiments.

[0047] The optical lens provided by the embodiment of the present invention is an in-screen fingerprint lens, which is used to identify fingerprints. The number of lenses with optical power is four. The optical lens sequentially includes, along the optical axis from the object side to the imaging surface: a first lens, a second lens, a third lens, and a fourth lens.

[0048] In some embodiments, the first lens may have a negative optical power. Its object side is convex, and its image side is concave. The second lens may have a positive optical power. Its object side is convex, and its image side is convex. The third lens may have a positive optical power. Its object side is convex, and its image side is convex near the optical axis. The fourth lens may have a positive optical power. Its object side is convex near the optical axis, and its image side may be concave or convex.

[0049] In some embodiments, the optical lens may further include a flat glass, which is disposed between the object side and the first lens. The protective glass serves to protect the optical lens.

[0050] In some embodiments, the optical lens may further include an aperture stop, which may be located between the second lens and the third lens. It can be understood that the aperture stop is used to limit the amount of incident light to change the brightness of the image. When the aperture stop is located between the second lens and the third lens, it is convenient for correcting the aperture aberration.

[0051] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 13.5 < TTL / f < 14.9. By limiting the ratio of the total length of the optical lens to the effective focal length of the optical lens to meet the above conditional formula, the total length of the optical lens can be effectively compressed, so that the optical lens can meet the thin and light design.

[0052] In some embodiments, the semi-object height OBH of the optical lens and the true image height IH corresponding to the maximum field angle of view of the optical lens satisfy: 3.2 < OBH / IH < 3.4. Specifically, the semi-object height refers to the perpendicular distance from the edge of the object to the optical axis, which is a quantization index of the object field of view in the optical lens. By reasonably controlling the relationship between the object height and the image height to meet the above conditional formula, the object height of the optical lens can be effectively increased, the recognition range can be increased, which is conducive to increasing the fingerprint recognition accuracy of the optical lens.

[0053] In some embodiments, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens satisfy: 2.95 mm < TTL / Fno < 3 mm. By controlling the relationship between the total length of the optical lens and the aperture value to meet the above conditional formula, it is ensured that the optical lens can meet the requirements of large aperture and miniaturization design, enabling the optical lens to obtain sufficient light transmission in a dim environment and meeting the needs of high-quality and high-definition shooting.

[0054] In some embodiments, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 103° < FOV / Fno < 105°. By reasonably controlling the relationship between the field angle of view and the aperture value of the optical lens to meet the above conditional formula, it is beneficial to achieve the balance of the large field angle and large aperture of the optical lens.

[0055] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2.3 < f1 / f < -2.1. By meeting the above conditional formula, the first lens has a negative optical power, which can diverge the light passing through it, expand the field angle of the optical lens, and simplify the overall aberration correction and imaging quality balance of the optical lens.

[0056] In some embodiments, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 54 < R1 / R2 < 92. By meeting the above conditional formula, the surface shapes of the object side and image side of the first lens can be constrained, which is beneficial to reducing the bending degree of light at the image side surface of the first lens, reducing the astigmatism of the optical lens, and balancing the astigmatism problem caused by the large field angle of the optical lens, so that the astigmatism is not too large while the optical lens has a large field of view, thereby ensuring that the optical lens has excellent imaging quality.

[0057] In some embodiments, the focal length f2 of the second lens, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 5.8 < (f2 + f3) / f < 6.3. By meeting the above conditional formula, the proportion of the focal lengths of the second lens and the third lens can be reasonably controlled, which is beneficial to correcting the spherical aberration of the central field of view of the optical lens and improving the imaging quality of the optical lens.

[0058] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 2.7 < f2 / f < 3.4; the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -3.5 < R4 / R3 < -2.6. By satisfying the above conditional expressions, the focal length and surface shape of the second lens can be reasonably controlled, which is beneficial to the gentle transition of light, reduces the sensitivity of the optical lens, and is conducive to regulating the field angle of the optical lens, reducing the field curvature and distortion of the marginal field, and improving the imaging quality of the optical lens.

[0059] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 170 < f4 / f < 210. By satisfying the above conditional expressions, by setting the fourth lens to have a large positive optical power, the light rays from the first three lenses can be further converged, the aberration problems brought by the first three lenses can be corrected, and the aberration of the marginal field can be effectively improved, thereby improving the overall imaging quality of the optical lens.

[0060] In some embodiments, the combined focal length f34 of the third lens and the fourth lens and the effective focal length f of the optical lens satisfy: 2.8 < f34 / f < 3.2. By satisfying the above conditional expressions, setting the combined focal length of the third lens and the fourth lens in the rear group of lenses to be a positive optical power is beneficial to correcting the chromatic aberration and field curvature of the optical lens, slowing down the light deflection angle, reducing the sensitivity, and achieving the balance of the overall spherical aberration, and obtaining good imaging quality in the axial field.

[0061] In some embodiments, the clear aperture semi-diameter CSD11 of the object side surface of the first lens and the distance CT12 between the first lens and the second lens on the optical axis satisfy: 1.55 < CSD11 / CT12 < 1.75. By satisfying the above conditional expressions, by controlling the clear aperture of the object side surface of the first lens and reducing the air gap between the first lens and the second lens, it is beneficial to reduce the total length of the optical lens, make the arrangement of the optical lens more compact, and reduce the risk of ghost image generation; furthermore, it is also beneficial to reduce the difficulty of the structural arrangement of the optical lens and improve the assembly molding yield of the optical lens.

[0062] In some embodiments, the sagittal height SAG11 of the clear aperture of the object side surface of the first lens and the central thickness CT1 of the first lens satisfy: 1.5 < SAG11 / CT1 < 2.8. By satisfying the above conditional expressions, controlling the ratio of the sagittal height of the object side surface of the first lens to the central thickness of the first lens on the optical axis can make the surface shape of the object side surface tend to be curved, and at the same time, a larger sagittal height is beneficial for the first lens to collect light in a large field of view, achieving high angular resolution at the center of the optical lens, and then improving the imaging quality of the central region.

[0063] 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: 4.4 < CSD11 / CSD41 < 4.6. 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, which is convenient for being mounted on an electronic device; at the same time, it is ensured 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.

[0064] In some embodiments, the edge thickness ET1 of the first lens and the central thickness CT1 of the first lens satisfy: 2.6 < ET1 / CT1 < 3.4. By satisfying the above conditional formula, by reasonably controlling the ratio of the edge thickness of the first lens and the thickness of the first lens on the optical axis, the thickness ratio of the first lens can be reasonably controlled, thereby optimizing the surface shape of the first lens, which is beneficial to the effective convergence of large-angle incident light, and making the light passing through the first lens have a smaller deflection angle, so as to reduce the generation of stray light, and further ensure good imaging performance.

[0065] In some embodiments, the semi-object height OBH of the optical lens and the total optical length TTL of the optical lens satisfy: 1.15 < OBH / TTL < 1.25. By satisfying the above conditional formula, by reasonably controlling the relationship between the object height and the total optical length, the object height of the optical lens can be effectively increased and it is ensured that the optical lens meets the miniaturization requirement.

[0066] In some embodiments, the optical lens satisfies the following conditional formulas: 0.26 mm < f < 0.33 mm; 135° < FOV < 140°; 0.19 mm < EPD < 0.23 mm; 3.95 mm < TTL < 4 mm; 1.3 < Fno < 1.35; 1.4 mm < IH < 1.55 mm; 4.7 mm < OBH < 4.8 mm. In the above conditional formulas, f represents the effective focal 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, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field angle of the optical lens; OBH represents the semi-object height of the optical lens. By satisfying the above conditional formulas, the optical lens has at least one or more advantages of short focal length, large field angle, large entrance pupil diameter, short total length, large aperture, large image plane, low distortion, and low sensitivity.

[0067] In some embodiments, the four lenses in the optical lens can all adopt plastic lenses or adopt a structure with a combination of glass and plastic materials. Specifically, the optical lens provided by the present invention can adopt an all-plastic lens structure, which can effectively reduce costs, correct aberrations, reduce volume, and provide an optical lens product with higher cost performance.

[0068] In some embodiments, the first, second, third, and fourth lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, the first, second, third, and fourth lenses in the optical lens provided by this invention can be aspherical lenses.

[0069] 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:

[0070] ;

[0071] 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.

[0072] 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.

[0073] Example 1

[0074] Please see Figure 1 and Figure 2 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging surface S9, the following components in sequence: a flat glass G1, a first lens L1, a second lens L2, an aperture ST, a third lens L3, and a fourth lens L4.

[0075] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0076] The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is convex.

[0077] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex near the optical axis.

[0078] The fourth lens L4 has positive optical power, its object side S7 is convex near the optical axis, and its image side S8 is concave near the optical axis.

[0079] The imaging plane S9 is a plane.

[0080] The first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are all plastic aspherical lenses.

[0081] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0082] Table 1-1

[0083]

[0084] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0085] Table 1-2

[0086]

[0087] In this embodiment, the field curvature curve, F-Tan(θ) distortion curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 100 are respectively as follows: Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown.

[0088] Figure 3 The field curvature curve of the optical lens 100 in Embodiment 1 is shown, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half-object height (the vertical distance from the edge of the object to the optical axis, unit: mm). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.4 mm to 0, indicating that the optical lens can effectively correct the field curvature.

[0089] Figure 4 The F-Tan(θ) distortion curve for Example 1 is shown, representing the F-Tan(θ) distortion of light at different image heights on the imaging plane. The horizontal axis represents the F-Tan(θ) distortion value (unit: %), and the vertical axis represents the half-object height (unit: mm). As can be seen from the figure, the F-Tan(θ) distortion of the optical lens is controlled within -1.5% to 2%, indicating that the optical lens can effectively correct distortion.

[0090] Figure 5The transverse chromatic aberration curve of Example 1 is shown, representing the chromatic aberration of each wavelength relative to the center wavelength (0.525 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 half-object height (unit: mm). As can be seen from the figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3 μm to 3 μm, indicating that the optical lens can effectively correct chromatic aberration.

[0091] Figure 6 The relative illumination curves for Example 1 are shown, representing the relative illumination values ​​at different field-of-view angles on the imaging plane. The horizontal axis represents half-object height (unit: mm), and the vertical axis represents relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is greater than 30%, indicating that the optical lens has good relative illumination.

[0092] Example 2

[0093] Please see Figure 7 and Figure 8 The figure shown is 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 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 200 in Example 2 are shown in Table 2-1.

[0095] Table 2-1

[0096]

[0097] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0098] Table 2-2

[0099]

[0100] In this embodiment, the field curvature curve, F-Tan(θ) distortion curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 200 are respectively as follows: Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown.

[0101] from Figure 9 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.4mm to 0mm, indicating that the optical lens can effectively correct the field curvature.

[0102] from Figure 10As can be seen, the F-Tan(θ) distortion of the optical lens is controlled within -1% to 2%, indicating that the optical lens can correct distortion well.

[0103] from Figure 11 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -2μm to 2μm, indicating that the optical lens can correct chromatic aberration well.

[0104] from Figure 12 As can be seen, the relative illumination value of the optical lens is greater than 30%, indicating that the optical lens has good relative illumination.

[0105] Example 3

[0106] Please see Figure 13 and Figure 14 The figure 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 image side surface S8 of the fourth lens L4 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0107] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0108] Table 3-1

[0109]

[0110] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0111] Table 3-2

[0112]

[0113] In this embodiment, the field curvature curve, F-Tan(θ) distortion curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 300 are respectively as follows: Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown.

[0114] from Figure 15 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.3mm to 0, indicating that the optical lens can effectively correct the field curvature.

[0115] from Figure 16 As can be seen, the F-Tan(θ) distortion of the optical lens is controlled within -1.5% to 2%, indicating that the optical lens can correct distortion well.

[0116] from Figure 17As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -2μm to 3μm, indicating that the optical lens can correct chromatic aberration well.

[0117] from Figure 18 As can be seen, the relative illumination value of the optical lens is greater than 30%, indicating that the optical lens has good relative illumination.

[0118] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, half-object height OBH, and the values ​​corresponding to each conditional expression in each embodiment.

[0119] Table 4

[0120]

[0121] In summary, the optical lens provided by the present invention uses four lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as a large field of view, short overall length, large aperture, large image plane, and high imaging quality.

[0122] 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.

[0123] 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.

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