Optical lens

Abstract

This invention provides an optical lens comprising seven lenses, arranged sequentially along the optical axis from the object side to the image plane: a first lens with negative optical power, its object side being convex and its image side being concave; a second lens with negative optical power, its image side being concave; a third lens with positive optical power, its object side being concave and its image side being convex; a fourth lens with negative optical power, its image side being concave; a fifth lens with positive optical power, its object side being convex and its image side being convex; a sixth lens with negative optical power, its object side being concave and its image side being convex; and a seventh lens with positive optical power. This invention achieves a large field of view, a large aperture, and miniaturization by rationally combining the lens shapes and optical powers of each lens.

Description

Technical Field

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

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure driver safety. However, some existing ADAS systems use wide-angle lenses, which suffer from significant aberrations, large field curvature, and poor image quality, failing to meet user needs. Therefore, there is a need to develop an optical lens with superior imaging performance. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide an optical lens that can solve at least one or more of the above problems.

[0005] To achieve the above objectives, the present invention provides an optical lens comprising seven lenses, arranged sequentially along the optical axis from the object side to the image plane: a first lens with negative optical power, having a convex object side and a concave image side; a second lens with negative optical power, having a concave image side; a third lens with positive optical power, having a concave object side and a convex image side; a fourth lens with negative optical power, having a concave image side; a fifth lens with positive optical power, having a convex object side and a convex image side; a sixth lens with negative optical power, having a concave object side and a convex image side; and a seventh lens with positive optical power, having a convex object side and a convex image side.

[0006] In some embodiments, the fifth lens and the sixth lens are cemented together to form a cemented lens.

[0007] In some embodiments, the aperture stop is disposed between the fourth lens and the fifth lens.

[0008] In some implementations, the total optical length (TTL) of the optical lens and the effective focal length (f) of the optical lens satisfy the condition: 11.0 < TTL / f < 16.0.

[0009] In some implementations, the image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view of the optical lens satisfy: 1.0 < (IH / 2) / (f×θ) < 1.20.

[0010] In some implementations, the maximum field of view (FOV) of the optical lens and the aperture value (FNO) of the optical lens satisfy the following condition: 100° < FOV / FNO < 115°.

[0011] In some implementations, the optical back focal length (BFL) of the optical lens and the effective focal length (f) of the optical lens satisfy the condition: 2.0 < BFL / f < 2.5.

[0012] In some implementations, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < -5.5.

[0013] In some implementations, the effective focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: f2 / f < -2.2.

[0014] In some implementations, the effective focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 4.0 < f3 / f.

[0015] In some implementations, the effective focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: f4 / f < -4.5.

[0016] In some implementations, the effective focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: f7 / f < 4.0.

[0017] In some implementations, the radius of curvature R4 of the image-side surface of the second lens satisfies the condition 1.0 < R4 / f with the effective focal length f of the optical lens.

[0018] In some implementations, the radius of curvature R8 of the image side of the fourth lens satisfies the condition 3.0 < R8 / f with the effective focal length f of the optical lens.

[0019] In some embodiments, the radius of curvature R5 of the object side of the third lens and the radius of curvature R6 of the image side of the third lens satisfy: 0 < (R5 - R6) / (R5 + R6) < 0.8.

[0020] In some embodiments, the radius of curvature R9 of the object side of the fifth lens and the radius of curvature R12 of the image side of the sixth lens satisfy: (R9-R12) / (R9+R12)<-2.0.

[0021] In some embodiments, the light transmission half-aperture sag5 of the object side of the third lens and the light transmission half-aperture d5 of the object side of the third lens satisfy: -0.05≤Sag5 / d5≤-0.01.

[0022] In some embodiments, the sum of the center thicknesses of the first to seventh lenses, ∑CT, satisfies the condition that the total optical length of the optical lens, TTL, is 0.50 < ∑CT / TTL < 0.60.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: The optical lens provided by the present invention uses seven lenses with optical power. By reasonably matching the optical power and surface shape of each lens, the optical lens has a compact structure while having good image quality. At the same time, by reasonably setting the aperture position, lens thickness and inter-lens spacing, the optical lens has an ultra-large field of view and a large aperture, achieving a balance between ultra-large field of view, large aperture, miniaturization and high pixel count, which can meet the imaging requirements of automotive lenses. Attached Figure Description

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

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

[0026] Figure 3 This is a distortion curve of the optical lens in Embodiment 1 of the present invention.

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

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

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

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

[0031] Figure 8 This is a distortion curve of the optical lens in Embodiment 2 of the present invention.

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

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

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

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

[0036] Figure 13 This is a distortion curve of the optical lens in Embodiment 3 of the present invention.

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

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

[0039] Figure 16 This is a schematic diagram of the optical lens structure of Embodiment 4 of the present invention.

[0040] Figure 17 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0041] Figure 18 This is a distortion curve of the optical lens in Embodiment 4 of the present invention.

[0042] Figure 19 This is a relative illumination curve of the optical lens in Embodiment 4 of the present invention.

[0043] Figure 20 This is the MTF curve of the optical lens in Embodiment 4 of the present invention. Detailed Implementation

[0044] To better understand the invention, various aspects of the invention 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 the invention and are not intended to limit the scope of the invention 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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 the invention, the word "may" is used to mean "one or more embodiments of the invention." And the term "exemplary" is intended to refer to an example or illustration.

[0049] 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 invention 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 defined herein.

[0050] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0051] This invention provides an optical lens, which, from the object side to the imaging plane, includes, in sequence: a first lens, a second lens, a third lens, a fourth lens, an aperture stop, a fifth lens, a sixth lens, a seventh lens, and a filter, and the optical centers of each lens are located on the same straight line.

[0052] In some embodiments, the first lens is configured to have negative optical power, with the object side being convex and the image side being concave. This allows for the acquisition of as much large-angle incident light as possible, expanding the field of view of the optical lens. At the same time, it can reduce the tendency of light to bend, reduce the difficulty of aberration correction by subsequent lenses, and improve the imaging quality of the optical lens.

[0053] In some embodiments, the second lens is configured to have negative optical power and a concave image side, which can effectively constrain large-angle light rays passing through the first lens and slow down the light turning trend to make the transition smooth.

[0054] In some embodiments, the third lens is configured to have positive optical power, with the object side being concave and the image side being convex. This can concentrate the light rays passing through the second lens, further reduce the tendency of light rays to change direction and make the transition smoother, while also correcting off-axis aberrations.

[0055] In some implementations, the fourth lens is configured to have negative optical power and a concave image side, which can further converge light rays, reduce the light ray height, and make the light ray path transition smoothly. At the same time, it can balance the spherical aberration and field curvature generated by the front lens and improve the imaging quality of the optical lens.

[0056] In some embodiments, the fifth lens and the sixth lens can be cemented together to form a cemented lens, which is used to share the chromatic aberration correction of the optical lens and improve the resolution of the optical lens. The fifth lens is configured to have positive optical power and a convex object side and a convex image side, while the sixth lens is configured to have negative optical power and a concave object side and a convex image side. This can converge the light rays emitted from the fourth lens and make them transition smoothly. At the same time, it can correct various aberrations caused by the front lens, reduce the loss of light in each field of view, improve the relative illumination of each field of view, and thus improve the imaging quality of the optical lens.

[0057] In some embodiments, the seventh lens is configured to have positive optical power, and the object side and image side are convex. This can effectively suppress the angle at which the edge field of view is incident on the imaging plane, effectively transmit more light beams to the imaging plane, and at the same time balance various aberrations of the optical lens, thereby improving the imaging quality of the optical lens.

[0058] In some embodiments, the aperture stop can be positioned between the fourth and fifth lenses to narrow the range of light emitted from the front lens, reduce the aperture of the rear lens, and balance the structure of the front and rear lens groups.

[0059] In some implementations, the aperture value FNO of the optical lens satisfies the following condition: 1.80 < FNO < 2.10. Meeting this range is beneficial for achieving large aperture characteristics, ensuring image clarity even in low-light environments or at night.

[0060] In some implementations, the maximum field of view (FOV) of the optical lens satisfies: 200° < FOV. Meeting this range facilitates the achievement of ultra-wide-angle characteristics, thereby enabling the acquisition of more scene information and meeting the needs of large-area detection.

[0061] In some implementations, the angle of incidence (CRA) of the principal ray at the maximum field of view of the optical lens on the image plane satisfies: 9° < CRA < 13°. Meeting this range allows for a larger tolerance range between the CRA of the optical lens and the CRA of the image sensor, improving the adaptability of the optical lens to the image sensor.

[0062] In some implementations, the total optical length (TTL) of the optical lens and the effective focal length (f) of the optical lens satisfy the condition: 11.0 < TTL / f < 16.0. Meeting this range can effectively limit the length and volume of the optical lens, enabling miniaturization of the optical lens.

[0063] In some implementations, the image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view of the optical lens satisfy: 1.0 < (IH / 2) / (f×θ) < 1.20. Satisfying the above range can balance the needs of large-area detection and high-quality imaging, and improve the adaptability of the optical lens.

[0064] In some implementations, the maximum field of view (FOV) of the optical lens and the aperture value (FNO) of the optical lens satisfy the following condition: 100° < FOV / FNO < 115°. Meeting this range helps to expand the field of view and increase the aperture of the optical lens, achieving ultra-wide-angle and large-aperture characteristics. The ultra-wide-angle characteristic allows the optical lens to acquire more scene information, meeting the needs of large-area detection. The large aperture characteristic helps to mitigate the problem of rapid brightness decrease at the edges of the field of view caused by wide-angle lenses, thus also facilitating the acquisition of more scene information.

[0065] In some embodiments, the optical back focal length (BFL) of the optical lens and the effective focal length (f) of the optical lens satisfy the condition: 2.0 < BFL / f < 2.5. Meeting this range allows the optical lens to have a longer optical back focal length, which is beneficial for the assembly of the optical lens.

[0066] In some embodiments, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < -5.5. Satisfying this range allows the first lens to have appropriate negative optical power, which helps to make the change in the refraction angle of the incident light more gradual, avoids excessive refraction changes that would produce too many aberrations, and at the same time helps more light to enter the rear lens, increasing the field of view of the optical lens and improving the relative illumination of the optical lens.

[0067] In some embodiments, the effective focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: f2 / f < -2.2. Satisfying this range allows the second lens to have appropriate negative optical power, which can share the negative optical power of the first lens, allowing light rays with a large field of view to enter the optical lens smoothly, thereby expanding the light collection range.

[0068] In some embodiments, the effective focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 4.0 < f3 / f. Satisfying this range allows the third lens to have appropriate positive optical power, which can balance the negative optical power at the front end of the optical lens, allowing light rays with a large field of view to smoothly enter the rear end of the optical lens.

[0069] In some embodiments, the effective focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: f4 / f < -4.5. Satisfying this range allows the fourth lens to have an appropriate negative optical power, which can diverge the light rays emitted through the fourth lens, causing the light rays to bend upwards, enlarging the physical aperture of the aperture stop, which is beneficial to increasing the relative illumination of the optical lens and improving image quality.

[0070] In some implementations, the effective focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: f7 / f < 4.0. Meeting this range allows the seventh lens to have appropriate positive optical power, which facilitates the rapid convergence of light to the image plane, reduces the upward trend of light rays, avoids excessive light energy loss caused by a large difference between the incident angle of large field-of-view rays and the chip's principal ray angle on the image plane, improves the illumination of the edge field of view, and facilitates the achievement of a short total optical length (TTL).

[0071] In some embodiments, the radius of curvature R4 of the image-side surface of the second lens satisfies the condition 1.0 < R4 / f with the effective focal length f of the optical lens. Satisfying this range can correct the aberrations produced by the first lens and improve the imaging quality of the optical lens.

[0072] In some embodiments, the radius of curvature R8 of the image-side surface of the fourth lens and the effective focal length f of the optical lens satisfy the condition: 3.0 < R8 / f. Satisfying this range can reduce the energy of ghost images projected onto the image plane due to reflections in the central region of the image-side surface of the fourth lens, thereby improving the imaging quality of the optical lens.

[0073] In some embodiments, the radius of curvature R5 of the object-side surface of the third lens and the radius of curvature R6 of the image-side surface of the third lens satisfy: 0 < (R5 - R6) / (R5 + R6) < 0.8. Meeting this range requires a small distance between the incident light ray and the optical axis, which is beneficial for reducing the lens's front aperture and allowing for a smooth transition of light within the lens. Simultaneously, it reduces the refraction of light on the object-side surface, thereby reducing aberrations and improving the imaging quality of the optical lens.

[0074] In some embodiments, the radius of curvature R9 of the object-side surface of the fifth lens and the radius of curvature R12 of the image-side surface of the sixth lens satisfy: (R9-R12) / (R9+R12) < -2.0. Meeting this range has a converging effect on light, which helps to reduce the aperture of the rear lens group, allowing the light emitted from the fourth lens to smoothly transition to the rear, thereby reducing sensitivity, reducing aberrations, and improving resolution. Simultaneously, the light emitted from the fourth lens is well received by the fifth lens, reducing light loss in each field of view and improving relative illumination in each field of view; it also reduces aberrations in the cemented parts and enhances the correction effect for chromatic aberration.

[0075] In some embodiments, the half-aperture sagitta Sag5 of the object side of the third lens and the half-aperture d5 of the object side of the third lens satisfy the following condition: -0.05 ≤ Sag5 / d5 ≤ -0.01. Meeting this range allows for the smooth reception of light emitted from the second lens, enabling the collected light to smoothly enter the rear lens, which helps to reduce the front aperture of the lens and allows for a smooth transition of light within the lens.

[0076] In some embodiments, the sum of the center thicknesses of the first to seventh lenses, ∑CT, satisfies the condition that the total optical length TTL of the optical lens is 0.50 < ∑CT / TTL < 0.60. Satisfying this range is beneficial for reducing the total length and volume of the optical lens, thus maintaining its miniaturization.

[0077] In one implementation, the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens and seventh lens can be made entirely of glass or a combination of glass and plastic, both of which can achieve good imaging results.

[0078] In one implementation, at least one of the object-side or image-side surfaces of the first, second, third, fifth, sixth, and seventh lenses is aspherical. Aspherical lenses are characterized by a continuously changing curvature from the lens center to the lens periphery. Unlike spherical lenses, which have a constant curvature from the lens center to the lens periphery, aspherical lenses possess superior curvature radius characteristics, offering advantages in improving distortion and astigmatism. By employing aspherical lenses, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality.

[0079] 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:

[0080]

[0081] 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, and F are the second, fourth, sixth, eighth, tenth, and twelfth order surface coefficients, respectively.

[0082] 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.

[0083] Example 1

[0084] Please see Figure 1 The diagram shows a schematic of the structure of an optical lens provided in Embodiment 1 of the present invention. The optical lens includes, along the optical axis from the object side to the imaging plane S16, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a filter G1.

[0085] Among them, the first lens L1 is a glass spherical lens with negative optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave; the second lens L2 is a glass aspherical lens with negative optical power, its object-side surface S3 is concave, and its image-side surface S4 is concave; the third lens L3 is a glass aspherical lens with positive optical power, its object-side surface S5 is concave, and its image-side surface S6 is convex; the fourth lens L4 is a glass spherical lens with negative optical power, its object-side surface S7 is convex, and its image-side surface S8 is convex; the fifth lens L5 is a glass aspherical lens with positive optical power. A glass spherical lens with positive optical power has an object-side surface S9 that is convex and an image-side surface that is convex. The sixth lens L6 is a glass spherical lens with negative optical power, with an object-side surface concave and an image-side surface S11 that is convex. The fifth lens L5 and the sixth lens L6 are cemented together to form a cemented lens, with the cementing surface being S10. The seventh lens L7 is a glass aspherical lens with positive optical power, with an object-side surface S12 that is concave near the optical axis and an image-side surface S13 that is convex. The filter G1 has an object-side surface S14 and an image-side surface S15 that are both flat.

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

[0087] Table 1-1

[0088]

[0089]

[0090] The surface coefficients of the aspherical lens in the optical lens of Example 1 are shown in Table 1-2.

[0091] Table 1-2

[0092]

[0093] 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 ±0.18 mm, indicating that the optical lens can effectively correct the field curvature.

[0094] Figure 3 The distortion curve of Example 1 is shown, which represents the F-θ 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 distortion value is controlled within ±20%, indicating that the optical lens has a large positive distortion.

[0095] Figure 4 The relative illumination curve of Example 1 is shown, which represents the relative illumination value at different field-of-view angles on the imaging plane. The horizontal axis represents the half-field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 40% at the maximum half-field angle, indicating that the optical lens has good relative illumination.

[0096] Figure 5 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 0.2 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.

[0097] Example 2

[0098] Please see Figure 6 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 2 of the present invention. The structure of the optical lens in this embodiment is roughly the same as that of the optical lens in Embodiment 1 above. The main differences are that the curvature radius, aspherical coefficient, thickness and material of each lens surface are different.

[0099] The relevant parameters of each lens in the optical lens of Example 2 are shown in Table 2-1.

[0100] Table 2-1

[0101]

[0102] The surface coefficients of the aspherical lens in the optical lens of Example 2 are shown in Table 2-2.

[0103] Table 2-2

[0104]

[0105] Figures 7 to 10 The field curvature curve, distortion curve, relative illumination curve, and modulation transfer function (MTF) curve for Example 2 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within ±0.15mm, indicating that the optical lens can effectively correct field curvature; the distortion value is controlled within ±20%, indicating that the optical lens has significant positive distortion; the relative illumination value of the optical lens is still greater than 40% at the maximum half-field angle, indicating that the optical lens has good relative illumination; the MTF value of the optical lens is above 0.2 throughout the entire field of view, and within the range of 0–160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0106] Example 3

[0107] Please see Figure 11 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 3 of the present invention. The structure of the optical lens in this embodiment is roughly the same as that of the optical lens in Embodiment 1 above. The main differences are that the curvature radius, aspherical coefficient, thickness and material of each lens surface are different.

[0108] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0109] Table 3-1

[0110]

[0111] The surface coefficients of the aspherical lens in Example 3 are shown in Table 3-2.

[0112] Table 3-2

[0113]

[0114]

[0115] Figures 12 to 15The field curvature curve, distortion curve, relative illumination curve, and modulation transfer function (MTF) curve of Example 3 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within ±0.12mm, indicating that the optical lens can effectively correct field curvature; the distortion value is controlled within ±10%, indicating that the optical lens has significant positive distortion; the relative illumination value of the optical lens is still greater than 50% at the maximum half-field angle, indicating that the optical lens has good relative illumination; the MTF value of the optical lens is above 0.3 throughout the entire field of view, and within the range of 0–160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0116] Example 4

[0117] Please see Figure 16 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 4 of the present invention. The structure of the optical lens in this embodiment is roughly the same as that of the optical lens in Embodiment 1 above. The main differences are that the curvature radius, aspherical coefficient, thickness and material of each lens surface are different.

[0118] The relevant parameters of each lens in the optical lens of Example 4 are shown in Table 4-1.

[0119] Table 4-1

[0120]

[0121]

[0122] The surface coefficients of the aspherical lens in Example 4 are shown in Table 4-2.

[0123] Table 4-2

[0124]

[0125] Figures 17 to 20 The field curvature curve, distortion curve, relative illumination curve, and modulation transfer function (MTF) curve of Example 4 are shown respectively. As can be seen from the figures, the field curvature of the meridional and sagittal image planes is controlled within ±0.12 mm, indicating that the optical lens can effectively correct field curvature; the distortion value is controlled within ±10%, indicating that the optical lens has significant positive distortion; the relative illumination value of the optical lens is still greater than 50% at the maximum half-field angle, indicating that the optical lens has good relative illumination; the MTF value of the optical lens is above 0.2 throughout the entire field of view, and within the range of 0–160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution at both low and high frequencies.

[0126] Please refer to Table 5, which shows the optical characteristics corresponding to the four embodiments above, including the effective focal length f of the optical lens, the maximum field of view FOV, the entrance pupil diameter EPD, the total optical length TTL, the aperture value FNO, the image height IH corresponding to the maximum field of view, the incident angle CRA of the principal ray on the image plane at the maximum field of view, and the values ​​corresponding to each conditional expression in each embodiment.

[0127] Table 5

[0128]

[0129]

[0130] In summary, the optical lens in this embodiment of the invention, by reasonably allocating the optical power of each lens, reasonably matching the surface shape of each lens, and reasonably setting the thickness of each lens and the spacing between each lens, and by adopting a combination structure of six glass spherical lenses and one glass aspherical lens, can achieve ultra-large field of view (maximum FOV value of 210°), large aperture (minimum FNO value of 1.86), miniaturization (minimum TTL value of 13.0mm) and high pixel count, thereby meeting the imaging requirements of automotive lenses.

[0131] 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.

[0132] 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, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging surface along the optical axis, there are: a first lens with negative refractive power, whose object side surface is convex and whose image side surface is concave; a second lens with negative refractive power, whose image side surface is concave; a third lens with positive refractive power, whose object side surface is concave and whose image side surface is convex; a fourth lens with negative refractive power, whose image side surface is concave; a fifth lens with positive refractive power, whose object side surface is convex and whose image side surface is convex; a sixth lens with negative refractive power, whose object side surface is concave and whose image side surface is convex; a seventh lens with positive refractive power; wherein the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 0 < (R5-R6) / (R5+R6) < 0.8; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -3.34 ≤ (R9-R12) / (R9+R12) < -2.0; the maximum field of view FOV of the optical lens and the aperture value FNO of the optical lens satisfy: 100° < FOV / FNO < 115°.

2. The optical lens of claim 1, wherein, the seventh lens has a convex object side surface and a convex image side surface.

3. The optical lens of claim 1, wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 11.0 < TTL / f < 16.

0.

4. The optical lens of claim 1, wherein, the maximum field of view FOV of the optical lens and the aperture value FNO of the optical lens satisfy: 105° ≤ FOV / FNO ≤ 112.9°.

5. The optical lens of claim 1, wherein, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 0.67 ≤ (R5-R6) / (R5+R6) ≤ 0.74; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -3.34 ≤ (R9-R12) / (R9+R12) ≤ -2.

19.

6. The optical lens of claim 1, wherein, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -6.70 ≤ f1 / f < -5.

5.

7. The optical lens of claim 1, wherein, the effective focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.87 ≤ f2 / f < -2.

2.

8. The optical lens of claim 1, wherein, the effective focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 4.0 < f3 / f ≤ 5.

49.

9. The optical lens of claim 1, wherein, the effective focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 3.02 ≤ f7 / f < 4.

0.

10. The optical lens of claim 1, wherein, the sum ∑CT of the central thicknesses of the first lens to the seventh lens and the total optical length TTL of the optical lens satisfy: 0.50 < ∑CT / TTL < 0.60.

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