Optical lens

Abstract

The application provides an optical lens, which comprises eight lenses in sequence from an object side to an imaging surface along an optical axis, wherein the first lens has positive focal power, the object side of the first lens is a convex surface, and the image side of the first lens is a concave surface; the second lens has negative focal power, the object side of the second lens is a convex surface, and the image side of the second lens is a concave surface; the third lens has positive focal power, the object side of the third lens is a convex surface, and the image side of the third lens is a concave surface; the fourth lens has positive focal power, the object side and the image side of the fourth lens are both convex surfaces; the fifth lens has negative focal power, the object side of the fifth lens is a concave surface, and the image side of the fifth lens is a convex surface; the sixth lens has negative focal power, the object side of the sixth lens is a convex surface, and the image side of the sixth lens is a concave surface; the seventh lens has positive focal power, the object side of the seventh lens is a convex surface, and the image side of the seventh lens is a concave surface; and the eighth lens has negative focal power, the object side and the image side of the eighth lens are both concave surfaces. The optical lens provided by the application is beneficial to miniaturization, has a large image height, improves the adaptation range with a chip element, has obvious aberration optimization effect, and has excellent imaging quality.

Description

Technical Field

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

[0002] In recent years, with the rapid upgrading of consumer electronics products such as mobile phones and tablets, the market demands for imaging lenses have become increasingly diversified. In addition to requiring imaging lenses to have a slim and compact form factor and high pixel count and high resolution, there are also requirements for the image quality of the imaging lenses in the products.

[0003] In view of this, the present invention proposes an optical lens with significant aberration optimization effect, large image height, and excellent imaging quality, while also taking into account miniaturization, making it suitable for portable electronic products. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens that features significant aberration optimization, large image height, and excellent imaging quality, while also being miniaturized and suitable for portable electronic products.

[0005] The purpose of this invention is to provide an optical lens comprising eight lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0006] The first lens with positive optical power has a convex object side and a concave image side.

[0007] A second lens with negative optical power has a convex object side and a concave image side.

[0008] A third lens with positive optical power has a convex object-side surface and a concave image-side surface;

[0009] The fourth lens with positive optical power has convex surfaces on both its object side and image side.

[0010] The fifth lens with negative optical power has a concave object side and a convex image side.

[0011] The sixth lens with negative optical power has a convex object side and a concave image side.

[0012] The seventh lens with positive optical power has a convex object side and a concave image side.

[0013] The eighth lens, which has negative optical power, has concave object-side and image-side surfaces.

[0014] Further preferably, the total optical length TTL of the optical lens and the effective focal length f satisfy: 1.0 < TTL / f < 1.3.

[0015] Further preferably, the true image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f satisfy: 1.8 < IH / f < 2.0.

[0016] Further preferably, the effective focal length f, the maximum field of view FOV, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 1.0≤(IH / 2) / (f×tan(FOV / 2))<1.05.

[0017] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2 < f2 / f < 0.

[0018] Further preferably, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.6 < f7 / f.

[0019] Further preferably, the focal length f7 of the seventh lens and the focal length f2 of the second lens satisfy: -0.6 < f2 / f7 < -1.1.

[0020] More preferably, the effective focal length f of the optical lens and the combined focal length f of the first lens to the third lens are... 13 Satisfy: 1.1 < f 13 / f<1.5.

[0021] More preferably, the effective focal length f of the optical lens and the combined focal length f of the sixth lens to the eighth lens are... 68 Satisfy: -1.1 < f 68 / f<-1.4.

[0022] More preferably, the combined focal length f of the first lens to the third lens is... 13 The combined focal length f with the sixth to eighth lenses 68 Satisfy: -0.9 < f 13 / f 68 <-1.2.

[0023] Further preferably, the maximum field of view (FOV) of the optical lens, the effective working aperture (D1) of the object side of the first lens, and the true image height (IH) corresponding to the maximum field of view satisfy: 0.25 < D1 / IH / tan(FOV / 2) < 0.35.

[0024] Further preferably, the total optical length TTL of the optical lens and the sum of the center thicknesses ∑CT of the first lens to the eighth lens along the optical axis satisfy: 0.5 < ∑CT / TTL < 0.6.

[0025] The optical lens provided by this invention can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens; it has a large image height, which improves the compatibility with chip components; and by reasonably matching the lens shape and optical power combination between each lens, aberrations are reduced and the imaging quality of the optical lens is improved. Attached Figure Description

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

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

[0028] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 3 This is the F-tanθ distortion curve of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 4 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 5 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0032] Figure 6 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0033] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0034] Figure 8 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 9 This is the F-tanθ distortion curve of the optical lens in Embodiment 2 of the present invention.

[0036] Figure 10 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0037] Figure 11 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0038] Figure 12 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0039] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0041] Figure 15 This is the F-tanθ distortion curve of the optical lens in Embodiment 3 of the present invention.

[0042] Figure 16 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0043] Figure 17 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0044] Figure 18 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention. Detailed Implementation

[0045] 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.

[0046] 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.

[0047] 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.

[0048] In this paper, 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 projection plane is called the projection side of the lens, and the surface of each lens closest to the image source plane is called the image source side of the lens.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] The optical lens according to the embodiments of this application comprises eight lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane: an aperture stop, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a filter.

[0053] 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 negative optical power, with its object-side surface being convex and its image-side surface being concave; the third lens may have positive optical power, with its object-side surface being convex and its image-side surface being concave; the fourth lens may have positive optical power, with both its object-side and image-side surfaces being convex; the fifth lens may have negative optical power, with its object-side surface being concave and its image-side surface being convex; the sixth lens may have negative optical power, with its object-side surface being convex and its image-side surface being concave; the seventh lens may have positive optical power, with its object-side surface being convex and its image-side surface being concave; and the eighth lens may have negative optical power, with both its object-side and image-side surfaces being concave.

[0054] In some embodiments, the total optical length (TTL) and effective focal length (f) of the optical lens satisfy the condition: 1.0 < TTL / f < 1.3. Meeting this range can effectively limit the length of the lens and achieve miniaturization of the optical lens.

[0055] In some embodiments, the true image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f satisfy: 1.8 < IH / f < 2.0. Satisfying the above range enables the realization of a large image plane characteristic and improves the imaging quality of the optical lens.

[0056] In some embodiments, the effective focal length f, maximum field of view (FOV), and the true image height IH corresponding to the maximum field of view of the optical lens satisfy the following condition: 1.0 ≤ (IH / 2) / (f × tan(FOV / 2)) < 1.05. Meeting this range indicates that the optical distortion of the optical lens is well controlled, thus improving the lens's resolving power.

[0057] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy the condition: -2 < f2 / f < 0. Satisfying this range allows the second lens to have appropriate negative optical power, which can increase the imaging area of ​​the optical lens; at the same time, it can effectively balance various aberrations of the optical lens and improve the imaging quality of the optical lens.

[0058] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy the condition: 1.6 < f7 / f. Meeting this range allows the seventh lens to have appropriate positive optical power, improving the light-gathering ability of the optical lens and shortening the overall length of the optical lens. It also significantly enhances distortion optimization and improves the image quality of the optical lens.

[0059] In some embodiments, the focal length f7 of the seventh lens and the focal length f2 of the second lens satisfy the condition: -0.6 < f2 / f7 < -1.1. Satisfying this range can balance the front and rear of the optical lens, reduce astigmatism and field curvature, and improve the imaging quality of the optical lens.

[0060] In some embodiments, the effective focal length f of the optical lens and the combined focal length f of the first to third lenses are... 13 Satisfy: 1.1 < f 13 / f < 1.5. Meeting the above range can significantly optimize spherical aberration in the first, second, and third lenses, thereby improving the imaging quality of the optical lens.

[0061] In some embodiments, the effective focal length f of the optical lens and the combined focal length f of the sixth to eighth lenses are... 68 Satisfy: -1.1 < f 68 / f < -1.4. Meeting the above range can significantly optimize astigmatism in the sixth, seventh, and eighth lenses, thereby improving the imaging quality of the optical lens.

[0062] In some embodiments, the combined focal length f of the first to third lenses is... 13 Combined focal length f with the sixth to eighth lenses 68Satisfy: -0.9 < f 13 / f 68 <-1.2. Meeting the above range can balance the front and back of the optical lens, reduce axial aberration of the lens, and improve the imaging quality of the optical lens.

[0063] In some embodiments, the maximum field of view (FOV) of the optical lens, the effective working aperture D1 of the object-side surface of the first lens, and the true image height IH corresponding to the maximum field of view satisfy the following condition: 0.25 < D1 / IH / tan(FOV / 2) < 0.35. Meeting this range allows for a small front aperture while maintaining a large field of view and a large image plane.

[0064] In some embodiments, the total optical length TTL of the optical lens and the sum of the center thicknesses ∑CT of the first to eighth lenses along the optical axis satisfy the following condition: 0.5 < ∑CT / TTL < 0.6. Satisfying this range can effectively compress the total length of the optical lens, while also benefiting the structural design and manufacturing process of the optical lens.

[0065] To achieve better optical performance, the lens employs multiple aspherical lenses, and the shapes of each aspherical surface of the optical lens satisfy the following equation:

[0066]

[0067] 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 A, B, C, D, E, F, G, and H are the second, fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0068] 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.

[0069] Example 1

[0070] Please see Figure 1 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 1 of the present invention. The optical lens 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, fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8 and filter G1.

[0071] Aperture ST;

[0072] The first lens L1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave; the second lens L2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave; the third lens L3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave; the fourth lens L4 has positive optical power, with both its object-side surface S7 and its image-side surface S8 being convex.

[0073] The fifth lens L5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex; the sixth lens L6 has negative optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave; the seventh lens L7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave; the eighth lens L8 has negative optical power, with both its object-side surface S15 and its image-side surface S16 being concave; the object-side surface S17 and its image-side surface S18 of the filter G1 are both planar.

[0074] The imaging plane S19 is a plane.

[0075] The relevant parameters of each lens in the optical lens of Example 1 are shown in Table 1-1.

[0076] Table 1-1

[0077]

[0078]

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

[0080] Table 1-2

[0081]

[0082] In this embodiment, the field curvature curve, F-tanθ distortion curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown.

[0083] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.08 mm, indicating that the optical lens can correct the field curvature very well.

[0084] Figure 3 The F-Tanθ distortion curves for Example 1 are shown, representing the F-Tanθ distortion of light of different wavelengths at different image heights on the image source plane. The horizontal axis represents F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within 2%, indicating that the optical lens can effectively correct F-tanθ distortion.

[0085] Figure 4 The modulation transfer function (MTF) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this example is above 0.4 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0086] Figure 5 The 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: μm), and the vertical axis represents the normalized pupil radius. The diagram shows that the axial aberration offset is controlled within ±15 μm, indicating that the optical lens can effectively correct axial aberrations.

[0087] Figure 6 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.55 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 ±1 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0088] Example 2

[0089] Please see Figure 7 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 2 of the present invention. The optical lens 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, fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8 and filter G1.

[0090] Aperture ST;

[0091] The first lens L1 has positive optical power, its object side S1 is convex, and its image side S2 is concave.

[0092] The second lens L2 has negative optical power, its object side S3 is convex, and its image side S4 is concave; the third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is concave; the fourth lens L4 has positive optical power, and both its object side S7 and image side S8 are convex.

[0093] The fifth lens L5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex; the sixth lens L6 has negative optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave; the seventh lens L7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave; the eighth lens L8 has negative optical power, with both its object-side surface S15 and its image-side surface S16 being concave; the object-side surface S17 and its image-side surface S18 of the filter G1 are both planar.

[0094] The imaging plane S19 is a plane.

[0095] The relevant parameters of each lens in the optical lens of Example 2 are shown in Table 2-1.

[0096] Table 2-1

[0097]

[0098]

[0099] The surface profile parameters of the aspherical lens in Example 2 are shown in Table 2-2.

[0100] Table 2-2

[0101]

[0102] In this embodiment, the field curvature curve, F-tanθ distortion curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown.

[0103] Figure 8 The field curvature curve of Example 2 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.05 mm, indicating that the optical lens can correct the field curvature very well.

[0104] Figure 9The F-Tanθ distortion curves for Example 2 are shown, representing the F-Tanθ distortion of light of different wavelengths at different image heights on the image source plane. The horizontal axis represents F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within 2%, indicating that the optical lens can effectively correct F-tanθ distortion.

[0105] Figure 10 The modulation transfer function (MTF) curve of Example 2 is shown, which represents the lens imaging modulation at different spatial frequencies in each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this example is above 0.4 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0106] Figure 11 The axial aberration curve of Example 2 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within ±17μm, indicating that the optical lens can effectively correct axial aberration.

[0107] Figure 12 The diagram shows the transverse chromatic aberration curves for Example 2, representing the chromatic aberration of each wavelength relative to the center wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value (unit: μm) of each wavelength relative to the center wavelength, 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 ±0.3 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0108] Example 3

[0109] Please see Figure 13 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 3 of the present invention. The optical lens 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, fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8 and filter G1.

[0110] Aperture ST;

[0111] The first lens L1 has positive optical power, its object side S1 is convex, and its image side S2 is concave.

[0112] The second lens L2 has negative optical power, its object side S3 is convex, and its image side S4 is concave; the third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is concave; the fourth lens L4 has positive optical power, and both its object side S7 and image side S8 are convex.

[0113] The fifth lens L5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex; the sixth lens L6 has negative optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave; the seventh lens L7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave; the eighth lens L8 has negative optical power, with both its object-side surface S15 and its image-side surface S16 being concave; the object-side surface S17 and its image-side surface S18 of the filter G1 are both planar.

[0114] The imaging plane S19 is a plane.

[0115] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0116] Table 3-1

[0117]

[0118]

[0119] The surface profile parameters of the aspherical lens in Example 3 are shown in Table 3-2.

[0120] Table 3-2

[0121]

[0122] In this embodiment, the field curvature curve, F-tanθ distortion curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown.

[0123] Figure 14 The field curvature curve of Example 3 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.06 mm, indicating that the optical lens can correct the field curvature very well.

[0124] Figure 15The F-Tanθ distortion curves for Example 3 are shown, representing the F-Tanθ distortion of light of different wavelengths at different image heights on the image source plane. The horizontal axis represents F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within 1.5%, indicating that the optical lens can effectively correct F-tanθ distortion.

[0125] Figure 16 The modulation transfer function (MTF) curve of Example 3 is shown, which represents the lens imaging modulation at different spatial frequencies in each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this example is above 0.4 throughout the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0126] Figure 17 The axial aberration curve of Example 3 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -5 to 23 μm, indicating that the optical lens can correct axial aberration well.

[0127] Figure 18 The diagram shows the transverse chromatic aberration curves for Example 3, representing the chromatic aberration of each wavelength relative to the center wavelength (0.55 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 ±0.3 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0128] 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, and maximum field of view FOV of the optical lens, as well as the values ​​corresponding to each conditional expression in each embodiment.

[0129] Table 4

[0130]

[0131]

[0132] In summary, the optical lens provided by the present invention can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens; it has a large image height, which improves the compatibility with chip components; and by reasonably matching the lens shape and optical power combination between each lens, aberrations are reduced and the imaging quality of the optical lens is improved.

[0133] 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.

[0134] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens comprising eight lenses, characterized in that, Along the optical axis from the object side to the imaging plane, the following are included in sequence: The first lens with positive optical power has a convex object side and a concave image side. A second lens with negative optical power has a convex object side and a concave image side. A third lens with positive optical power has a convex object-side surface and a concave image-side surface; The fourth lens with positive optical power has convex surfaces on both its object side and image side. The fifth lens with negative optical power has a concave object side and a convex image side. The sixth lens with negative optical power has a convex object side and a concave image side. The seventh lens with positive optical power has a convex object side and a concave image side. The eighth lens, which has negative optical power, has concave object-side and image-side surfaces; The true image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f satisfy: 1.8 < IH / f < 2.

0.

2. The optical lens according to claim 1, characterized in that, The total optical length TTL and the effective focal length f of the optical lens satisfy the following condition: 1.0 < TTL / f < 1.

3.

3. The optical lens according to claim 1, characterized in that, The effective focal length f, maximum field of view FOV, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 1.0≤(IH / 2) / (f×tan(FOV / 2))<1.

05.

4. The optical lens according to claim 1, characterized in that, The focal length f7 of the seventh lens and the focal length f2 of the second lens satisfy the condition: -0.6 < f2 / f7 < -1.

1.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the combined focal length f of the first lens to the third lens 13 Satisfy: 1.1 < f 13 / f<1.

5.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the combined focal length f of the sixth to eighth lenses 68 Satisfy: -1.1 < f 68 / f<-1.

4.

7. The optical lens according to claim 1, characterized in that, The combined focal length f of the first lens to the third lens 13 The combined focal length f with the sixth to eighth lenses 68 Satisfy: -0.9 < f 13 / f 68 <-1.

2.

8. The optical lens according to claim 1, characterized in that, The maximum field of view (FOV) of the optical lens, the effective working aperture (D1) of the object side of the first lens, and the true image height (IH) corresponding to the maximum field of view satisfy the following condition: 0.25 < D1 / IH / tan(FOV / 2) < 0.

35.

9. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens and the sum of the center thicknesses of the first lens to the eighth lens along the optical axis, ∑CT, satisfy the following condition: 0.5 < ∑CT / TTL < 0.6.

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