Optical lens

Abstract

The utility model discloses an optical lens. Comprising a first lens with negative focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with positive focal power, a fifth lens with positive focal power, a sixth lens with negative focal power and a seventh lens with positive focal power which are sequentially arranged from an object space to an image space along an optical axis, the first to sixth lenses are glass spherical mirrors, the seventh lens is a glass aspherical mirror, and the fifth lens and the sixth lens are cemented to form a cemented lens. The optical lens can be matched with a large chip, has high resolution, and also has the characteristics of low cost, small size, no large resolution deviation at high and low temperatures and the like.

Description

Technical Field

[0001] The utility model relates to the field of optical technologies, and particularly to an optical lens. Background Art

[0002] With the rapid development of automotive assisted driving, in-vehicle lenses are increasingly widely used, and people's requirements for lenses are also getting higher and higher. At present, the performance of conventional in-vehicle lenses is relatively low and can no longer meet the market demand. Content of the Utility Model

[0003] The utility model provides an optical lens, which can match a large chip, has high resolution, and can also take into account characteristics such as low cost, small volume, and no large deviation in resolution at high and low temperatures.

[0004] An optical lens according to the utility model includes: a first lens with a negative focal power, a second lens with a negative focal power, a third lens with a positive focal power, a fourth lens with a positive focal power, a fifth lens with a positive focal power, a sixth lens with a negative focal power, and a seventh lens with a positive focal power, which are arranged in sequence from the object side to the image side along the optical axis. Among them, the first lens to the sixth lens are glass spherical lenses, the seventh lens is a glass aspherical lens, and the fifth lens and the sixth lens are glued together to form a glued lens.

[0005] Optionally, the object side surface of the first lens is convex, the image side surface is concave, the object side surface of the second lens is concave, the image side surface is convex, the object side surface of the third lens is convex, the image side surface is concave, the object side surface of the fourth lens is convex, the image side surface is convex or flat, the object side surface of the fifth lens is convex, the image side surface is convex, the object side surface of the sixth lens is concave, and the image side surface is concave.

[0006] Optionally, the focal powers of the first lens to the seventh lens satisfy:

[0007]

[0008]

[0009]

[0010] Wherein, is the focal power of the optical lens, are the focal powers of the first lens to the seventh lens respectively in sequence.

[0011] Optionally, the refractive indices and Abbe numbers of the first lens to the seventh lens satisfy:

[0012] 1.78 ≤ n1 ≤ 1.96; 29.7 ≤ v1 ≤ 48.7; 1.71 ≤ n2 ≤ 1.85; 46.6 ≤ v2 ≤ 56.6;

[0013] 1.82 ≤ n3 ≤ 1.95; 25.3 ≤ v3 ≤ 45.7; 1.54 ≤ n4 ≤ 1.67; 56.4 ≤ v4 ≤ 75.3;

[0014] 1.45 ≤ n5 ≤ 1.67; 56.4 ≤ v5 ≤ 85.6; 1.79 ≤ n6 ≤ 1.96; 16.9 ≤ v6 ≤ 25.8;

[0015] 1.55 ≤ n7 ≤ 1.66; 55.3 ≤ v7 ≤ 66.2;

[0016] Wherein, n1, n2, n3, n4, n5, n6, n7 are the refractive indices of the first lens to the seventh lens in sequence, and v1, v2, v3, v4, v5, v6, v7 are the Abbe numbers of the first lens to the seventh lens in sequence.

[0017] Optionally, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: 1 ≤ |R4 / R3| ≤ 3.

[0018] Optionally, the curvature radius R10 of the object side surface of the fifth lens and the curvature radius R11 of the image side surface of the fifth lens satisfy: 0.5 ≤ |R10 / R11| ≤ 2.

[0019] Optionally, the image plane diameter IC of the optical lens and the focal length f of the optical lens satisfy the following condition: 2.1 ≤ IC / f ≤ 2.7.

[0020] Optionally, the central thickness T3 of the third lens, the central thickness T4 of the fourth lens, the central thickness T5 of the fifth lens and the total length TTL of the optical lens satisfy the following condition: 0.15 ≤ (T3 + T4 + T5) / TTL ≤ 0.27.

[0021] Optionally, the back focal length BFL of the optical lens and the total length TTL of the optical lens satisfy the following condition: BFL / TTL ≥ 0.13.

[0022] Optionally, the optical lens further includes: a diaphragm, and the diaphragm is located between the third lens and the fourth lens.

[0023] The optical lens according to the present utility model includes: a first lens with a negative optical power, a second lens with a negative optical power, a third lens with a positive optical power, a fourth lens with a positive optical power, a fifth lens with a positive optical power, a sixth lens with a negative optical power, and a seventh lens with a positive optical power, which are arranged in sequence from the object side to the image side along the optical axis. Among them, the first lens to the sixth lens are glass spherical lenses, the seventh lens is a glass aspherical lens, and the fifth lens and the sixth lens are glued together to form a cemented lens. Among them, the optical lens can match a large chip, has high resolution, and can also take into account low cost, small volume, and no large deviation in resolution at high and low temperatures.

[0024] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present utility model, nor is it used to limit the scope of the present utility model. Other features of the present utility model will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 is a schematic structural diagram of the optical lens provided by the embodiment of the present utility model;

[0027] Figure 2 is a schematic structural diagram of the optical lens proposed in Embodiment 1 of the present utility model;

[0028] Figures 3 to 9 is the fan diagram of the optical lens proposed in Embodiment 1 of the present utility model;

[0029] Figure 10 is the spherical aberration curve diagram of the optical lens proposed in Embodiment 1 of the present utility model;

[0030] Figure 11 is a schematic structural diagram of the optical lens proposed in Embodiment 2 of the present utility model;

[0031] Figures 12 to 18 is the fan diagram of the optical lens proposed in Embodiment 2 of the present utility model;

[0032] Figure 19 is the spherical aberration curve diagram of the optical lens proposed in Embodiment 2 of the present utility model;

[0033] Figure 20 is a schematic structural diagram of the optical lens proposed in Embodiment 3 of the present utility model;

[0034] Figures 21 to 27 is the fan diagram of the optical lens proposed in Embodiment 3 of the present utility model;

[0035] Figure 28 is the spherical aberration curve graph of the optical lens proposed in Embodiment 3 of the present utility model. Detailed implementation manners

[0036] In order to enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0037] It should be noted that the terms "first", "second", etc. in the description and claims of the present utility model and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present utility model described herein can be implemented in an order other than those illustrated or described herein.

[0038] Figure 1 is the structural schematic diagram of the optical lens provided according to the embodiment of the present utility model. As Figure 1 shown, the optical lens includes: a first lens L1 with a negative optical power, a second lens L2 with a negative optical power, a third lens L3 with a positive optical power, a fourth lens L4 with a positive optical power, a fifth lens L5 with a positive optical power, a sixth lens L6 with a negative optical power, and a seventh lens L7 with a positive optical power, which are arranged in sequence from the object side to the image side along the optical axis. Among them, the first lens L1 to the sixth lens L6 are glass spherical mirrors, the seventh lens L7 is a glass aspherical mirror, and the fifth lens L5 and the sixth lens L6 are glued together to form a glued lens.

[0039] Among them, the optical power is equal to the difference between the convergence degree of the image-side light beam and the convergence degree of the object-side light beam, and it characterizes the ability of the optical system to deflect light rays. The larger the absolute value of the optical power, the stronger the bending ability of the light rays; the smaller the absolute value of the optical power, the weaker the bending ability of the light rays. When the optical power is positive, the refraction of the light rays is convergent; when the optical power is negative, the refraction of the light rays is divergent. The optical power can be used to characterize a certain refracting surface of a lens (i.e., a surface of the lens), can be used to characterize a certain lens, or can be used to characterize a system formed by multiple lenses together (i.e., a lens group). In this embodiment, each lens can be fixed in a lens barrel ( Figure 1Inside (not shown in the figure), by reasonably distributing the optical power of the lenses, the imaging effect of the optical lens is better. Here, the optical power is the reciprocal of the focal length. In addition, the lenses are indirectly supported by mylar sheets or spacer rings. By distributing the optical power of each lens in the above way, the light can propagate smoothly without excessive deflection on a certain surface, and the imaging quality is good, which is beneficial to reducing aberration and lowering sensitivity.

[0040] In addition, the first lens L1 has a negative optical power and has a diverging effect on light. The second lens L2 has a negative optical power and has a diverging effect on light. Furthermore, after passing through the second lens L2, the light still maintains an upward trend, and the light can reach a higher position on the image plane when entering the rear optical system. The third lens L3 has a positive optical power and has a converging effect on light, enabling the light to smoothly enter the rear optical system, depressing the incident height of the light, reducing the rear aperture, and realizing miniaturization. The fourth lens L4 has a positive optical power and has a further converging effect on light, enabling the light to smoothly transition to the rear lens, improving the image quality, realizing a larger light input, and also reducing the angle between the large-angle light and the optical axis, which is beneficial to the miniaturization of the subsequent lens and the further reduction of the front aperture of the lens. The fifth lens L5 has a positive optical power and has a converging effect on light, capable of further depressing the incident height of the light, reducing the rear aperture, and realizing miniaturization. The sixth lens L6 has a negative optical power and has a diverging effect on light, capable of cooperating with the fifth lens L5 with a positive optical power to reduce aberration. The seventh lens L7 has a positive optical power and has a converging effect on light, enabling the light diverged by the sixth lens L6 to smoothly transition to the image plane.

[0041] Among them, the fifth lens L5 and the sixth lens L6 are cemented to form a cemented lens, making the overall structure of the optical lens compact, meeting the miniaturization requirements, and at the same time reducing the sensitivity problems of the fifth lens L5 and the sixth lens L6 due to tilting, eccentricity and other tolerances generated during the assembly process.

[0042] Among them, all the first lens L1 to the seventh lens L7 are made of glass lenses, which can adapt to different temperature occasions, have good temperature control, and have a high service life and stability. And the first lens L1 to the sixth lens L6 are spherical lenses, and the seventh lens L7 is an aspherical lens, which can reduce the processing cost, effectively correct astigmatism and field curvature, and is beneficial to improving the resolution ability of the optical lens.

[0043] Optionally, the object side of the first lens L1 is convex, the image side is concave, the object side of the second lens L2 is concave, the image side is convex, the object side of the third lens L3 is convex, the image side is concave, the object side of the fourth lens L4 is convex, the image side is convex or flat, the object side of the fifth lens L5 is convex, the image side is convex, and the object side of the sixth lens L6 is concave, the image side is concave.

[0044] Among them, the first lens L1 is set as a convex-concave lens, which is beneficial to collecting light rays in the peripheral field of view and can compress the height of the peripheral field of view light rays incident on the image plane, which is beneficial to achieving a large field of view angle. The second lens L2 is a concave-convex lens, which is beneficial to collecting the light rays emitted by the first lens L1, and can also reduce the front port diameter of the lens, reduce the volume, and is beneficial to miniaturization. The third lens L3 is a convex-concave lens, and the object side of the third lens L3 significantly changes the light ray trend, which is beneficial to reducing the front and rear port diameters of the lens and achieving lens miniaturization. The fourth lens L4 is a double convex lens or a convex plano-convex lens, which is beneficial to the convergence of light rays and is beneficial to reducing the front and rear port diameters of the lens to achieve lens miniaturization. The fifth lens L5 is a double convex lens, which is beneficial to the smooth transition of light rays backward. The sixth lens L6 is a double concave lens, which is beneficial to reducing the rear port diameter to achieve lens miniaturization. At the same time, the cooperation between the fifth lens L5 and the sixth lens L6 can reduce aberration and reduce the sensitivity to tolerances.

[0045] Optionally, the optical powers of the first lens L1 to the seventh lens L7 satisfy:

[0046]

[0047]

[0048]

[0049] Among them, is the optical power of the optical lens, are the optical powers of the first lens L1 to the seventh lens L7 in sequence.

[0050] Among them, by reasonably arranging the optical powers of the first lens L1 to the seventh lens L7, the light rays can be stable during propagation, without excessive deflection on a certain surface, and the imaging quality is good, which is beneficial to reducing aberration and reducing sensitivity.

[0051] Optionally, the refractive indices and Abbe numbers of the first lens L1 to the seventh lens L7 satisfy:

[0052] 1.78 ≤ n1 ≤ 1.96; 29.7 ≤ v1 ≤ 48.7; 1.71 ≤ n2 ≤ 1.85; 46.6 ≤ v2 ≤ 56.6;

[0053] 1.82 ≤ n3 ≤ 1.95; 25.3 ≤ v3 ≤ 45.7; 1.54 ≤ n4 ≤ 1.67; 56.4 ≤ v4 ≤ 75.3;

[0054] 1.45 ≤ n5 ≤ 1.67; 56.4 ≤ v5 ≤ 85.6; 1.79 ≤ n6 ≤ 1.96; 16.9 ≤ v6 ≤ 25.8;

[0055] 1.55 ≤ n7 ≤ 1.66; 55.3 ≤ v7 ≤ 66.2;

[0056] Wherein, n1, n2, n3, n4, n5, n6, and n7 are the refractive indices of the first lens L1 to the seventh lens L7 in sequence, and v1, v2, v3, v4, v5, v6, and v7 are the Abbe numbers of the first lens L1 to the seventh lens L7 in sequence.

[0057] Among them, by reasonably configuring the refractive indices and Abbe numbers of the first lens L1 to the seventh lens L7, better correction of chromatic aberration of the optical lens can be achieved.

[0058] Optionally, the following condition is satisfied between the curvature radius R3 of the object side of the second lens L2 and the curvature radius R4 of the image side of the second lens L2: 1 ≤ |R4 / R3| ≤ 3.

[0059] Among them, defining the curvature radius of the object side and the curvature radius of the image side of the second lens L2 is beneficial to collecting the light rays emitted by the first lens L1, and can also achieve a reduction in the front port diameter of the lens, reducing the volume and facilitating miniaturization.

[0060] Optionally, the following condition is satisfied between the curvature radius R10 of the object side of the fifth lens L5 and the curvature radius R11 of the image side of the fifth lens L5: 0.5 ≤ |R10 / R11| ≤ 2.

[0061] Among them, defining the curvature radius of the object side and the curvature radius of the image side of the fifth lens L5 is beneficial to the smooth transition of light rays to the rear.

[0062] Optionally, the image surface diameter IC of the optical lens and the lens focal length f of the optical lens satisfy the following condition: 2.1 ≤ IC / f ≤ 2.7.

[0063] Among them, defining the relationship between the image surface diameter IC and the focal length f of the optical lens is beneficial to resolution.

[0064] Optionally, the following condition is satisfied between the central thickness T3 of the third lens L3, the central thickness T4 of the fourth lens L4, the central thickness T5 of the fifth lens L5 and the total length TTL of the optical lens: 0.15 ≤ (T3 + T4 + T5) / TTL ≤ 0.27. It is beneficial to assist light rays in entering the optical lens and effectively correct astigmatism to improve imaging quality.

[0065] Optionally, the following condition is satisfied between the back focal length BFL of the optical lens and the total length TTL of the optical lens: BFL / TTL ≥ 0.13. It can meet the requirements of the back focal length of the optical lens, and can also reserve space for the installation and focusing of optical elements, avoid mechanical interference, and ensure assembly stability. That is, it can ensure that the imaging sensor IMA and the flat filter 100 have sufficient installation space.

[0066] Optionally, the optical lens further includes: a stop STO, and the stop STO is located between the third lens L3 and the fourth lens L4.

[0067] The optical lens according to the present invention includes: a first lens L1 with a negative optical power, a second lens L2 with a negative optical power, a third lens L3 with a positive optical power, a fourth lens L4 with a positive optical power, a fifth lens L5 with a positive optical power, a sixth lens L6 with a negative optical power, and a seventh lens L7 with a positive optical power, which are arranged in sequence from the object side to the image side along the optical axis. Among them, the first lens L1 to the sixth lens L6 are glass spherical lenses, the seventh lens L7 is a glass aspherical lens, and the fifth lens L5 and the sixth lens L6 are glued together to form a glued lens. Among them, the optical lens can match a large chip, has high resolution, and can also take into account characteristics such as low cost, small volume, and no large deviation in resolution at high and low temperatures.

[0068] The optical lens proposed by the present invention will be described below with specific embodiments.

[0069] Embodiment 1

[0070] Figure 2 is a schematic structural diagram of the optical lens according to Embodiment 1 of the present invention. As Figure 2 shown, the optical lens includes the first lens L1 to the seventh lens L7. The aperture FN0 of the optical lens is 1.60, and the total length is 30.796 mm.

[0071] Among them, the optical powers of the first lens L1 to the seventh lens L7 satisfy: The curvature radius R3 of the object side of the second lens L2 and the curvature radius R4 of the image side of the second lens L2 satisfy: |R4 / R3| = 1.682. The curvature radius R10 of the object side of the fifth lens L5 and the curvature radius R11 of the image side of the fifth lens L5 satisfy: |R10 / R11| = 1.072. The image plane diameter IC of the optical lens and the lens focal length f of the optical lens satisfy the following conditions: IC / f = 2.296. The central thickness T3 of the third lens L3, the central thickness T4 of the fourth lens L4, the central thickness T5 of the fifth lens L5 and the total length TTL of the optical lens satisfy the following conditions: (T3 + T4 + T5) / TTL = 0.196. The back focal length BFL of the optical lens and the total length TTL of the optical lens satisfy the following conditions: BFL / TTL = 0.137. The physical parameters of each lens of the optical lens in Embodiment 1 are shown in Table 1.

[0072] Table 1 Physical parameters of each lens of the optical lens in Embodiment 1

[0073] Surface number Surface type Radius of curvature Thickness Material (n) Material (v) S1 Spherical surface 18.583 0.900 1.869 33.512 S2 Spherical surface 4.671 4.727 S3 Spherical surface -8.284 5.802 1.717 54.600 S4 Spherical surface -13.938 0.917 S5 Spherical surface 10.323 2.206 1.870 27.657 S6 Spherical surface 63.274 1.936 Aperture STO Spherical surface Infinity 0.437 S8 Spherical surface 10.972 2.048 1.616 67.951 S9 Spherical surface Infinity 0.096 S10 Spherical surface 8.455 1.781 1.591 58.400 S11 Spherical surface -9.061 0.700 1.849 18.617 S12 Spherical surface 11.871 1.735 S13 Aspherical surface 13.707 3.292 1.649 56.000 S14 Aspherical surface -41.278 0.824 S15 Plane Infinity 0.800 1.517 64.199 S16 Plane Infinity 2.597 S17 Image plane Infinity

[0074] Among them, in Table 1, the surface serial numbers are numbered according to the surface order of each lens. For example, the surface serial number "S1" represents the object side surface of the first lens, the surface serial number "S2" represents the image side surface of the first lens, and so on; "STO" represents the aperture stop of the lens; the radius of curvature represents the degree of curvature of the lens surface. A positive value represents that the surface bends towards the object side, and the center of the circle is close to the image side. A negative value represents that the surface bends towards the image side, and the center of the circle is close to the object side. The thickness represents the central axial distance from the current surface to the next surface; the material (n) represents the refractive index, that is, the ability of the material between the current surface and the next surface to deflect light. A space represents that the current position is air and the refractive index is 1; the material (v) represents the Abbe number, that is, the dispersion characteristic of the material between the current surface and the next surface to light. A space represents that the current position is air.

[0075] The aspheric formula is as follows:

[0076]

[0077] Among them, z represents the axial sagittal height of the aspheric surface in the Z direction; r represents the distance from a point on the aspheric surface to the optical axis; c represents the curvature of the fitted spherical surface, and numerically it is the reciprocal of the radius of curvature; k represents the fitted conic coefficient; A, B, C, D, E, F, G respectively represent the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order coefficients of the aspheric polynomial.

[0078] The aspheric coefficients of the seventh lens L7 are shown in Table 2.

[0079] Table 2 Aspheric coefficients of the seventh lens L7 of the optical lens in the first embodiment

[0080]

[0081] Figures 3 to 9 is the fan diagram of the optical lens proposed in the first embodiment of the present invention. Among them, the blue lines in the figure represent light with a wavelength of 436 nm, the green lines represent light with a wavelength of 486 nm, the red lines represent light with a wavelength of 546 nm, the yellow lines represent light with a wavelength of 588 nm, and the purple lines represent light with a wavelength of 656 nm. The light fan diagram is one of the commonly used evaluation methods by current optical designers. In a single figure, the abscissa is the normalized beam aperture, and the ordinate is the vertical aberration. Ideally, each curve should completely coincide with the horizontal axis. At this time, all the light rays in the field of view are focused at the same point on the image plane; the ordinate in a single image can also be expressed as the maximum dispersion range of the beam on the ideal image plane. The fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also represent the magnitude of the vertical chromatic aberration. From Figures 3 to 9It can be seen that this optical lens is well - approximated to the abscissa at each wavelength in each field of view, indicating that the vertical aberration at each wavelength is well - corrected (±30μm). In addition, the curves of each color do not show obvious dispersion, indicating that this optical lens also has good correction for chromatic aberration, ensuring the imaging requirement of clear imaging in the full wavelength band of this optical lens.

[0082] Figure 10 It is the spherical aberration curve graph of the optical lens proposed in the first embodiment of the present invention. The vertical direction represents the normalization of the aperture, 0 represents on the optical axis, and the vertex in the vertical direction represents the maximum pupil radius (1.2592mm); the horizontal direction represents the offset relative to the ideal focus, with the unit of millimeter (mm). Different linear curves in the figure represent different wavelengths of the system imaging, from Figure 10 It can be seen that the axial aberrations of different wavelengths (436nm, 487nm, 546nm, 587nm to 656nm) are all controlled within the range of (-0.05mm, +0.05mm), indicating that the spherical aberration of this optical lens at each wavelength is well - controlled and can meet the requirements of wide - spectrum applications.

[0083] Embodiment 2

[0084] Figure 11 It is the structural schematic diagram of the optical lens proposed in the second embodiment of the present invention. As Figure 11 shown, this optical lens includes the first lens L1 to the seventh lens L7. The aperture FN0 of this optical lens is 1.65, and the total length is 30.790mm.

[0085] Among them, the optical powers of the first lens L1 to the seventh lens L7 satisfy: The curvature radius R3 of the object side of the second lens L2 and the curvature radius R4 of the image side of the second lens L2 satisfy: |R4 / R3| = 1.416. The curvature radius R10 of the object side of the fifth lens L5 and the curvature radius R11 of the image side of the fifth lens L5 satisfy: |R10 / R11| = 0.622. The image surface diameter IC of the optical lens and the focal length f of the optical lens satisfy the following condition: IC / f = 2.295. The central thickness T3 of the third lens L3, the central thickness T4 of the fourth lens L4, the central thickness T5 of the fifth lens L5 and the total length TTL of the optical lens satisfy the following condition: (T3 + T4 + T5) / TTL = 0.222. The back focal length BFL of the optical lens and the total length TTL of the optical lens satisfy the following condition: BFL / TTL = 0.133. The physical parameters of each lens of the optical lens in Embodiment 2 are shown in Table 3.

[0086] Table 3 Physical parameters of each lens of the optical lens in Embodiment 2

[0087]

[0088]

[0089] Among them, in Table 3, the surface numbers are numbered according to the surface order of each lens. For example, the surface number "S1" represents the object side surface of the first lens, the surface number "S2" represents the image side surface of the first lens, and so on; "STO" represents the aperture stop of the lens; the radius of curvature represents the degree of curvature of the lens surface. A positive value represents that the surface bends towards the object side, and the center of the circle is close to the image side. A negative value represents that the surface bends towards the image side, and the center of the circle is close to the object side. The thickness represents the central axial distance from the current surface to the next surface; the material (n) represents the refractive index, that is, the ability of the material between the current surface and the next surface to deflect light. A space represents that the current position is air and the refractive index is 1; the material (v) represents the Abbe number, that is, the dispersion characteristic of the material between the current surface and the next surface to light. A space represents that the current position is air.

[0090] The aspheric formula is as follows:

[0091]

[0092] Among them, z represents the axial sagittal height of the aspheric surface in the Z direction; r represents the distance from a point on the aspheric surface to the optical axis; c represents the curvature of the fitted spherical surface, and numerically it is the reciprocal of the radius of curvature; k represents the fitted conic coefficient; A, B, C, D, E, F, G respectively represent the 4th order, 6th order, 8th order, 10th order, 12th order, 14th order, and 16th order coefficients of the aspheric polynomial.

[0093] The aspheric coefficients of the seventh lens L7 are shown in Table 4.

[0094] Table 4 Aspheric Coefficients of the Seventh Lens L7 of the Optical Lens in the Second Embodiment

[0095]

[0096] Figures 12 to 18 is the fan diagram of the optical lens proposed in the second embodiment of the present invention. Among them, the blue lines in the figure represent light with a wavelength of 436 nm, the green lines represent light with a wavelength of 486 nm, the red lines represent light with a wavelength of 546 nm, the yellow lines represent light with a wavelength of 588 nm, and the purple lines represent light with a wavelength of 656 nm. The ray fan diagram is one of the commonly used evaluation methods by current optical designers. In a single figure, the abscissa is the normalized beam aperture, and the ordinate is the lateral aberration. Ideally, each curve should completely coincide with the horizontal axis. At this time, all rays in the field of view focus on the same point on the image plane; the ordinate in a single image can also be expressed as the maximum dispersion range of the beam on the ideal image plane. The fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also represent the magnitude of the lateral chromatic aberration. From Figures 12 to 18It can be seen that this optical lens is well - approximated to the abscissa at each wavelength in each field of view, indicating that the vertical aberration of each wavelength is well corrected (±30μm). In addition, the curves of each color do not show obvious dispersion, indicating that this optical lens also has good correction for chromatic aberration, ensuring the imaging requirement of clear imaging in the full wavelength band of this optical lens.

[0097] Figure 19 It is the spherical aberration curve graph of the optical lens proposed in the second embodiment of the present invention. The vertical direction represents the normalization of the aperture, 0 represents on the optical axis, and the vertex in the vertical direction represents the maximum pupil radius (1.2214mm); the horizontal direction represents the offset relative to the ideal focus, with the unit of millimeter (mm). Different linear curves in the figure represent different wavelengths of the system imaging, from Figure 19 It can be seen that the axial aberrations of different wavelengths (436nm, 487nm, 546nm, 587nm to 656nm) are all controlled within the range of (-0.05mm, +0.05mm), indicating that the spherical aberration of this optical lens at each wavelength is well controlled and can meet the requirements of wide - spectrum applications.

[0098] Embodiment Three

[0099] Figure 20 It is the structural schematic diagram of the optical lens proposed in the third embodiment of the present invention. As Figure 20 shown, this optical lens includes the first lens L1 to the seventh lens L7. The aperture FN0 of this optical lens is 1.64, and the total length is 30.855mm.

[0100] Among them, the optical powers of the first lens L1 to the seventh lens L7 satisfy: The curvature radius R3 of the object side of the second lens L2 and the curvature radius R4 of the image side of the second lens L2 satisfy: |R4 / R3| = 1.675. The curvature radius R10 of the object side of the fifth lens L5 and the curvature radius R11 of the image side of the fifth lens L5 satisfy: |R10 / R11| = 1.483. The image plane diameter IC of the optical lens and the focal length f of the optical lens satisfy the following condition: IC / f = 2.295. The central thickness T3 of the third lens L3, the central thickness T4 of the fourth lens L4, the central thickness T5 of the fifth lens L5 and the total length TTL of the optical lens satisfy the following condition: (T3 + T4 + T5) / TTL = 0.210. The back focal length BFL of the optical lens and the total length TTL of the optical lens satisfy the following condition: BFL / TTL = 0.132. The physical parameters of each lens of the optical lens in Embodiment Three are shown in Table 5.

[0101] Table 5 Physical parameters of each lens of the optical lens in Embodiment Three

[0102]

[0103]

[0104] Among them, in Table 5, the surface numbers are numbered according to the surface order of each lens. For example, the surface number "S1" represents the object side surface of the first lens, the surface number "S2" represents the image side surface of the first lens, and so on; "STO" represents the aperture of the lens; the radius of curvature represents the degree of curvature of the lens surface. A positive value indicates that the surface bends towards the object side, and the center is close to the image side. A negative value indicates that the surface bends towards the image side, and the center is close to the object side. The thickness represents the central axial distance from the current surface to the next surface; the material (n) represents the refractive index, that is, the ability of the material between the current surface and the next surface to refract light. A space represents that the current position is air and the refractive index is 1; the material (v) represents the Abbe number, that is, the dispersion characteristic of the material between the current surface and the next surface to light. A space represents that the current position is air.

[0105] The aspheric formula is as follows:

[0106]

[0107] Among them, z represents the axial sagittal height of the aspheric surface in the Z direction; r represents the distance from a point on the aspheric surface to the optical axis; c represents the curvature of the fitted spherical surface, and numerically it is the reciprocal of the radius of curvature; k represents the fitted conic coefficient; A, B, C, D, E, F, G respectively represent the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order coefficients of the aspheric polynomial.

[0108] The aspheric coefficients of the seventh lens L7 are shown in Table 6.

[0109] Table 6 Aspheric Coefficients of the Seventh Lens L7 in the Third Embodiment of the Optical Lens

[0110]

[0111]

[0112] Figures 21 to 27It is the fan diagram of the optical lens proposed in the third embodiment of the present utility model. Among them, the blue lines in the figure represent light with a wavelength of 436 nm, the green lines represent light with a wavelength of 486 nm, the red lines represent light with a wavelength of 546 nm, the yellow lines represent light with a wavelength of 588 nm, and the purple lines represent light with a wavelength of 656 nm. The ray fan diagram is one of the commonly used evaluation methods by current optical designers. In a single figure, the abscissa is the normalized beam aperture, and the ordinate is the lateral aberration. Ideally, each curve should completely coincide with the horizontal axis. At this time, all rays in the field of view focus at the same point on the image plane; the ordinate in a single image can also be expressed as the maximum dispersion range of the beam on the ideal image plane. The fan diagram can not only reflect the monochromatic aberration of different wavelengths but also represent the magnitude of the lateral chromatic aberration. From Figures 21 to 27 It can be seen that in this optical lens, at each field of view, each wavelength is well approximated to the horizontal axis, indicating that the lateral aberration of each wavelength is well corrected (±30 μm). In addition, there is no obvious dispersion in the curves of each color, indicating that this optical lens also has good correction for chromatic aberration, ensuring the imaging requirement of clear imaging in the full wavelength range of this optical lens.

[0113] Figure 28 It is the spherical aberration curve diagram of the optical lens proposed in the third embodiment of the present utility model. The vertical direction represents the normalization of the aperture, 0 represents on the optical axis, and the vertex in the vertical direction represents the maximum pupil radius (1.2289 mm); the horizontal direction represents the offset relative to the ideal focus, with the unit of millimeter (mm). Different linear curves in the figure represent different wavelengths of the system imaging. From Figure 28 It can be seen that the axial aberrations of different wavelengths (436 nm, 487 nm, 546 nm, 587 nm to 656 nm) are all controlled within the range of (-0.05 mm, +0.05 mm), indicating that the spherical aberration of this optical lens at each wavelength is well controlled and can meet the requirements of wide-spectrum applications.

[0114] The parameters in Embodiments 1 to 3 are summarized as shown in Table 7.

[0115] Table 7 Summary of Parameters in Embodiments 1 to 3

[0116]

[0117]

[0118] The above specific implementation manners do not constitute a limitation to the protection scope of the present utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An optical lens, characterized in that, Including: A first lens with a negative focal power, a second lens with a negative focal power, a third lens with a positive focal power, a fourth lens with a positive focal power, a fifth lens with a positive focal power, a sixth lens with a negative focal power, and a seventh lens with a positive focal power, which are arranged in sequence from the object side to the image side along the optical axis. Among them, the first lens to the sixth lens are glass spherical mirrors, the seventh lens is a glass aspherical mirror, and the fifth lens and the sixth lens are cemented to form a cemented lens.

2. The optical lens according to claim 1, wherein The object side surface of the first lens is convex, and the image side surface is concave. The object side surface of the second lens is concave, and the image side surface is convex. The object side surface of the third lens is convex, and the image side surface is concave. The object side surface of the fourth lens is convex, and the image side surface is convex or flat. The object side surface of the fifth lens is convex, and the image side surface is convex. The object side surface of the sixth lens is concave, and the image side surface is concave.

3. The optical lens according to claim 1, wherein The focal powers of the first lens to the seventh lens satisfy: -0.66 ≤ φ1 / φ ≤ -0.52; -0.11 ≤ φ2 / φ ≤ -0.02; 0.20 ≤ φ3 / φ ≤ 0.31; 0.21 ≤ φ4 / φ ≤ 0.36; 0.44 ≤ φ5 / φ ≤ 0.57; -0.79 ≤ φ6 / φ ≤ -0.50; 0.16 ≤ φ7 / φ ≤ 0.36; Where φ is the focal power of the optical lens, and φ1, φ2, φ3, φ4, φ5, φ6, φ7 are the focal powers of the first lens to the seventh lens respectively in sequence.

4. The optical lens according to claim 1, wherein The refractive indices and Abbe numbers of the first lens to the seventh lens satisfy: 1.78 ≤ n1 ≤ 1.96; 29.7 ≤ v1 ≤ 48.7; 1.71 ≤ n2 ≤ 1.85; 46.6 ≤ v2 ≤ 56.6; 1.82 ≤ n3 ≤ 1.95; 25.3 ≤ v3 ≤ 45.7; 1.54 ≤ n4 ≤ 1.67; 56.4 ≤ v4 ≤ 75.3; 1.45 ≤ n5 ≤ 1.67; 56.4 ≤ v5 ≤ 85.6; 1.79 ≤ n6 ≤ 1.96; 16.9 ≤ v6 ≤ 25.8; 1.55 ≤ n7 ≤ 1.66; 55.3 ≤ v7 ≤ 66.2; Where n1, n2, n3, n4, n5, n6, n7 are the refractive indices of the first lens to the seventh lens respectively in sequence, and v1, v2, v3, v4, v5, v6, v7 are the Abbe numbers of the first lens to the seventh lens respectively in sequence.

5. The optical lens according to claim 1, wherein Between the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens, it satisfies: 1 ≤ |R4 / R3| ≤ 3.

6. The optical lens according to claim 1, wherein Between the curvature radius R10 of the object side surface of the fifth lens and the curvature radius R11 of the image side surface of the fifth lens, it satisfies: 0.5 ≤ |R10 / R11| ≤ 2.

7. The optical lens according to claim 1, wherein, The image plane diameter IC of the optical lens and the lens focal length f of the optical lens satisfy the following condition: 2.1 ≤ IC / f ≤ 2.

7.

8. The optical lens according to claim 1, wherein The center thickness T3 of the third lens, the center thickness T4 of the fourth lens, the center thickness T5 of the fifth lens and the overall length TTL of the optical lens satisfy the following condition: 0.15 ≤ (T3 + T4 + T5) / TTL ≤ 0.

27.

9. The optical lens according to claim 1, characterized in that, The back focal length BFL of the optical lens and the overall length TTL of the optical lens satisfy the following condition: BFL / TTL ≥ 0.

13.

10. The optical lens according to claim 1, characterized in that, Further comprising: A diaphragm, which is located between the third lens and the fourth lens.

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