Wide-angle perception lens

Abstract

The application discloses a wide-angle perception lens, which comprises a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along an optical axis from an object side to an image side, wherein the first lens has a negative refractive power, the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a positive refractive power, the fifth lens has a positive refractive power, the sixth lens has a negative refractive power, and the seventh lens has a positive refractive power; and the second lens, the fourth lens and the seventh lens are all aspherical lenses. The wide-angle perception lens has the advantages of small outer diameter, short total length, high resolution (pixel can reach more than 8M), uniform picture quality of central and edge fields of view, large light transmission, good low-illumination effect, no defocus in a working temperature range of -40 DEG C to 105 DEG C, and no thermalization design.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, and more specifically, to a wide-angle sensing lens. Background Technology

[0002] With the continuous advancement of science and technology and the continuous development of society, optical imaging lenses have also developed rapidly in recent years. Among them, lenses are increasingly widely used in automobiles. With the rapid development of automotive driver assistance systems, the requirements for related automotive lenses are also becoming higher and higher. However, automotive lenses generally have the following problems: low lens resolution, generally between 2M and 5M; the development of lenses towards large target area and high resolution brings about the problems of complex lens structure and large size, making it impossible to simultaneously achieve large target area, high resolution and small size; low light transmission, low energy utilization, and poor low-light performance; in addition, automotive lenses have a wide range of high and low temperature operating conditions, requiring them to meet the operating temperature range of -40℃ to +105°, while existing automotive lenses are prone to defocusing in high and low temperature environments.

[0003] In view of this, the inventors of this application have invented a wide-angle sensing lens. Summary of the Invention

[0004] The purpose of this invention is to provide a wide-angle sensing lens that is small in size, has high resolution, good low-light performance, and achieves a heat-free design.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a wide-angle sensing lens, comprising a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along an optical axis from the object side to the image side. Each of the first lens to the seventh lens includes an object side facing the object side and allowing imaging light to pass through, and an image side facing the image side and allowing imaging light to pass through.

[0006] The first lens has negative refractive power, and the object side of the first lens is convex, while the image side is concave.

[0007] The second lens has negative refractive power, and the object side of the second lens is concave, while the image side is convex.

[0008] The third lens has positive refractive power, and the object side and the image side of the third lens are both convex.

[0009] The fourth lens has positive refractive power, and the object side and the image side of the fourth lens are both convex.

[0010] The fifth lens has positive refractive power, and the object side and the image side of the fifth lens are both convex.

[0011] The sixth lens has a negative refractive power, and the object side surface of the sixth lens is concave, and the image side surface is concave;

[0012] The seventh lens has a positive refractive power, and the object side surface of the seventh lens is convex, and the image side surface is convex;

[0013] Among them, the second lens, the fourth lens and the seventh lens are all aspherical lenses.

[0014] Furthermore, the first lens satisfies: nd1 > 1.8, where nd1 is the refractive index of the first lens.

[0015] Furthermore, the second lens satisfies: 0.05 ≤ (G21 / D2) ≤ 0.3, where G21 is the sagittal height of the second lens, and D2 is the outer diameter of the second lens.

[0016] Furthermore, the fourth lens is a positive lens, and when the ambient temperature is -40°C to 105°C, its refractive index temperature coefficient dn / dT satisfies: dn / dT < -2×10E-6.

[0017] Furthermore, the fourth lens satisfies: 0.7 < T4 / BFL < 1.2, where T4 is the central thickness of the fourth lens, and BFL is the back focal length of the lens optics.

[0018] Furthermore, the fourth lens satisfies: 2.0 < f4 / f < 3.0, where f4 is the focal length of the fourth lens, and f is the system focal length.

[0019] Furthermore, the image side surface of the fifth lens is adhesively bonded to the object side surface of the sixth lens, and the refractive index temperature coefficient Dn / dt of the fifth lens is negative, and the refractive index temperature coefficient Dn / dt of the sixth lens is positive.

[0020] Furthermore, the image side surface of the fifth lens is adhesively bonded to the object side surface of the sixth lens, and satisfies: |Vd6 - Vd5| > 30, where Vd5 is the dispersion coefficient of the fifth lens, and Vd6 is the dispersion coefficient of the sixth lens.

[0021] Furthermore, the lens satisfies: TTL / h ≤ 3.7, where TTL is the total optical length of the lens, and h is the designed image height of the optical lens.

[0022] Furthermore, the lens satisfies: BFL / TTL > 0.12, where BFL is the back focal length of the lens optics, and TTL is the total optical length of the lens.

[0023] After adopting the above technical solutions, compared with the prior art, the present invention has the following advantages:

[0024] The wide-angle sensing lens of this invention has a small outer diameter and short overall length, achieving miniaturization, and has high resolution, with a pixel count of over 8M. It has uniform image quality in the center and edge fields of view, large light transmission, and good low-light performance. In addition, it will not lose focus in an operating temperature range of -40℃ to 105℃, achieving a heat-free design. Attached Figure Description

[0025] Figure 1 This is the optical path diagram of Embodiment 1 of the present invention;

[0026] Figure 2 This is an axial chromatic aberration curve of the lens under visible light in Embodiment 1 of the present invention;

[0027] Figure 3 This is the MTF curve of the lens in Embodiment 1 of the present invention under visible light;

[0028] Figure 4 This is the optical path diagram of Embodiment 2 of the present invention;

[0029] Figure 5 This is an axial chromatic aberration curve of the lens under visible light in Embodiment 2 of the present invention;

[0030] Figure 6 This is the MTF curve of the lens in Embodiment 2 of the present invention under visible light;

[0031] Figure 7 This is the optical path diagram of Embodiment 3 of the present invention;

[0032] Figure 8 This is an axial chromatic aberration curve of the lens under visible light in Embodiment 3 of the present invention;

[0033] Figure 9 This is the MTF curve of the lens in Embodiment 3 of the present invention under visible light;

[0034] Figure 10 This is the optical path diagram of Embodiment 4 of the present invention;

[0035] Figure 11 This is an axial chromatic aberration curve of the lens under visible light in Embodiment 4 of the present invention;

[0036] Figure 12 This is the MTF curve of the lens in Embodiment 4 of the present invention under visible light.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens; 8. Aperture; 9. Protective plate. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] The phrase "a lens has a positive (or negative) refractive index" refers to the lens having a positive (or negative) paraxial refractive index calculated using Gaussian optics theory. The "object-side surface (or image-side surface)" is defined as the specific area through which imaging rays pass on the lens surface. The convexity or concavity of a lens surface can be determined using methods commonly employed in the field, namely by the sign of the radius of curvature (R-value). R-values ​​are commonly used in optical design software such as Zemax or CodeV. R-values ​​are also frequently found in lens data sheets within optical design software. For the object-side surface, a positive R-value indicates a convex surface, while a negative R-value indicates a concave surface. Conversely, for the image-side surface, a positive R-value indicates a concave surface, while a negative R-value indicates a convex surface.

[0041] The present invention discloses a wide-angle sensing lens, comprising a first lens 1, a second lens 2, a third lens 3, an aperture 8, a fourth lens 4, a fifth lens 5, a sixth lens 6, and a seventh lens 7 arranged sequentially along an optical axis from the object side to the image side. Each of the first lens 1 to the seventh lens 7 includes an object side facing the object side and allowing imaging light to pass through, and an image side facing the image side and allowing imaging light to pass through.

[0042] The first lens 1 has negative refractive power, and the object side of the first lens 1 is convex, while the image side is concave.

[0043] The second lens 2 has negative refractive power, and the object side of the second lens 2 is concave, while the image side is convex.

[0044] The third lens 3 has positive refractive power, and the object side and the image side of the third lens 3 are convex.

[0045] The fourth lens 4 has positive refractive power, and the object side and the image side of the fourth lens 4 are convex.

[0046] The fifth lens 5 has positive refractive power, and the object side and the image side of the fifth lens 5 are convex.

[0047] The sixth lens 6 has negative refractive power, and the object side and image side of the sixth lens 6 are concave.

[0048] The seventh lens 7 has positive refractive power, and the object side and the image side of the seventh lens 7 are convex.

[0049] Reasonably distribute the diopter and shape of each lens to improve system performance.

[0050] Among them, the second lens 2, the fourth lens 4, and the seventh lens 7 are all aspherical lenses, and the other lenses are all spherical lenses. For the second lens 2, the fourth lens 4, and the seventh lens 7 of this lens, all three lenses are aspherical lenses, which can greatly shorten the outer diameter and total length of the system, and can effectively correct aberrations such as spherical aberration, field curvature, and distortion generated by the front lenses, making the imaging of the edges clearer.

[0051] In some embodiments, the first lens 1 satisfies: nd1 > 1.8, where nd1 is the refractive index of the first lens 1. The first lens 1 is located at the front end of the lens, and its design with a high refractive index can effectively reduce the outer diameter of the lens.

[0052] In some embodiments, the second lens 2 satisfies: 0.05 ≤ (G21 / D2) ≤ 0.3, where G21 is the sag height of the second lens 2 and D2 is the outer diameter of the second lens 2. This is beneficial to the miniaturization of the lens.

[0053] In some embodiments, the fourth lens 4 is a positive lens, and when the ambient temperature is -40°C to 105°C, its refractive index temperature coefficient dn / dT satisfies: dn / dT < -2*10E-6. Materials that meet the above refractive index temperature coefficient are such as: H-ZPK5 / H-FK61, or other suitable materials; the fourth lens 4 meeting the above conditions can effectively balance the temperature drift and achieve athermalization.

[0054] The fourth lens 4 satisfies: 0.7 < T4 / BFL < 1.2, where T4 is the central thickness of the fourth lens and BFL is the back focal length of the lens optics. This is beneficial to the miniaturization of the lens.

[0055] The fourth lens 4 satisfies: 2.0 < f4 / f < 3.0, where f4 is the focal length of the fourth lens 4 and f is the system focal length.

[0056] In some embodiments, the image side of the fifth lens 5 and the object side of the sixth lens 6 are glued together, and the refractive index temperature coefficient Dn / dt of the fifth lens 5 is negative, and the refractive index temperature coefficient Dn / dt of the sixth lens 6 is positive. That is, the material for making the fifth lens 5 has a negative refractive index temperature coefficient Dn / dt, and the material for making the sixth lens 6 has a positive refractive index temperature coefficient Dn / dt. The fifth lens 5 and the sixth lens 6 form a glued lens. On the one hand, the glued lens can correct aberrations and improve the resolution, and on the other hand, it can make the lens more miniaturized; at the same time, the glued lens material is selected with a combination of a positive and a negative refractive index temperature coefficient, which can correct the temperature drift and achieve an athermal design.

[0057] In some embodiments, the image-side surface of the fifth lens 5 and the object-side surface of the sixth lens 6 are cemented together, satisfying |Vd6 - Vd5| > 30, where Vd5 is the dispersion coefficient of the fifth lens 5 and Vd6 is the dispersion coefficient of the sixth lens 6. Cemented lenses utilize a combination of high and low dispersion materials, which is beneficial for correcting chromatic aberration and optimizing image quality. Simultaneously, cementing reduces tolerance sensitivity and can retain some chromatic aberration to balance the chromatic aberration of the optical system, thus reducing tolerance sensitivity issues such as tilting / eccentricity that occur during lens assembly.

[0058] In some embodiments, the lens satisfies: TTL / h ≤ 3.7, where TTL is the total optical length of the lens and h is the designed image height of the optical lens. Satisfying this relationship is beneficial for lens miniaturization.

[0059] In some embodiments, the lens satisfies the condition that BFL / TTL > 0.12, where BFL is the optical back focal length of the lens and TTL is the total optical length of the lens. Satisfying this relationship allows the lens to be made smaller, meeting miniaturization requirements.

[0060] This lens is designed to meet the requirements of automotive-grade large-chip sensors, with high resolution, a pixel count of over 8M, and uniform image quality in both the center and edge fields of view.

[0061] The lens has a small outer diameter, short overall length, and small size, which can avoid the impact of an excessively large lens on driving.

[0062] The lens has a maximum aperture of F1.6, excellent low-light performance, and will not lose focus in automotive-grade operating temperatures ranging from -40°C to 105°C, achieving a heat-free design.

[0063] The wide-angle sensing lens of the present invention will now be described in detail with reference to specific embodiments.

[0064] Example 1

[0065] Reference Figure 1 As shown, the present invention discloses a wide-angle sensing lens, including a first lens 1, a second lens 2, a third lens 3, an aperture 8, a fourth lens 4, a fifth lens 5, a sixth lens 6, and a seventh lens 7 arranged sequentially along an optical axis from the object side to the image side. Each of the first lens 1 to the seventh lens 7 includes an object side facing the object side and allowing imaging light to pass through, and an image side facing the image side and allowing imaging light to pass through.

[0066] The first lens 1 has negative refractive power, and the object side of the first lens 1 is convex, while the image side is concave.

[0067] The second lens 2 has negative refractive power, and the object side of the second lens 2 is concave, while the image side is convex.

[0068] The third lens 3 has positive refractive power, and the object side and the image side of the third lens 3 are convex.

[0069] The fourth lens 4 has positive refractive power, and the object side and the image side of the fourth lens 4 are convex.

[0070] The fifth lens 5 has positive refractive power, and the object side and the image side of the fifth lens 5 are convex.

[0071] The sixth lens 6 has negative refractive power, and the object side and image side of the sixth lens 6 are concave.

[0072] The seventh lens 7 has positive refractive power, and the object side and the image side of the seventh lens 7 are convex.

[0073] Detailed optical data for this specific embodiment are shown in Table 1-1.

[0074] Table 1-1 Detailed optical data for Example 1

[0075]

[0076] The aspherical data in this embodiment are shown in Table 1-2.

[0077] Table 1-2 Aspherical data from Example 1

[0078]

[0079] In this embodiment, the values ​​of some lens parameters and their relationships are as follows:

[0080]

[0081] In this embodiment, please refer to the axial chromatic aberration curve of the lens under visible light. Figure 2 As can be seen from the figure, the axial color difference is less than ±0.04mm, indicating good color reproduction, small color difference, and no obvious blue-purple edge phenomenon.

[0082] Please refer to the MTF curve of the lens under visible light. Figure 3 As can be seen from the figure, when the spatial frequency of this lens reaches 110 lp / mm, the MTF value is greater than 0.55, indicating excellent image quality and high lens resolution.

[0083] Example 2

[0084] like Figure 4 As shown, the main difference between this embodiment and Embodiment 1 lies in the optical parameters such as the radius of curvature and lens thickness of each lens surface.

[0085] Detailed optical data for this specific embodiment are shown in Table 2-1.

[0086] Table 2-1 Detailed optical data for Example 2

[0087]

[0088] The aspherical data in this embodiment are shown in Table 2-2.

[0089] Table 2-2 Aspherical data from Example 2

[0090]

[0091] In this embodiment, the values ​​of some lens parameters and their relationships are as follows:

[0092]

[0093] In this embodiment, please refer to the axial chromatic aberration curve of the lens under visible light. Figure 5 As can be seen from the figure, the axial color difference is less than ±0.04mm, indicating good color reproduction, small color difference, and no obvious blue-purple edge phenomenon.

[0094] Please refer to the MTF curve of the lens under visible light. Figure 6 As can be seen from the figure, when the spatial frequency of this lens reaches 110 lp / mm, the MTF value is greater than 0.55, indicating excellent image quality and high lens resolution.

[0095] Example 3

[0096] like Figure 7 As shown, the main difference between this embodiment and Embodiment 1 lies in the optical parameters such as the radius of curvature and lens thickness of each lens surface.

[0097] Detailed optical data for this specific embodiment are shown in Table 3-1.

[0098] Table 3-1 Detailed optical data for Example 3

[0099]

[0100] The aspherical data in this embodiment are shown in Table 3-2.

[0101] Table 3-2 Aspherical data for Example 3

[0102]

[0103] In this embodiment, the values ​​of some lens parameters and their relationships are as follows:

[0104]

[0105] In this embodiment, please refer to the axial chromatic aberration curve of the lens under visible light. Figure 8 As can be seen from the figure, the axial color difference is less than ±0.05mm, indicating good color reproduction, small color difference, and no obvious blue-purple edge phenomenon.

[0106] Please refer to the MTF curve of the lens under visible light. Figure 9 As can be seen from the figure, when the spatial frequency of this lens reaches 110 lp / mm, the MTF value is around 0.6, indicating excellent image quality and high lens resolution.

[0107] Example 4

[0108] like Figure 10 As shown, the main difference between this embodiment and Embodiment 1 lies in the optical parameters such as the radius of curvature and lens thickness of each lens surface.

[0109] Detailed optical data for this specific embodiment are shown in Table 4-1.

[0110] Table 4-1 Detailed optical data for Example 4

[0111]

[0112] The aspherical data in this embodiment are shown in Table 4-2.

[0113] Table 4-2 Aspherical data for Example 4

[0114]

[0115] In this embodiment, the values ​​of some lens parameters and their relationships are as follows:

[0116]

[0117] In this embodiment, please refer to the axial chromatic aberration curve of the lens under visible light. Figure 11 As can be seen from the figure, the axial color difference is less than ±0.05mm, indicating good color reproduction, small color difference, and no obvious blue-purple edge phenomenon.

[0118] Please refer to the MTF curve of the lens under visible light. Figure 12 As can be seen from the figure, when the spatial frequency of this lens reaches 110 lp / mm, the MTF value is around 0.6, indicating excellent image quality and high lens resolution.

[0119] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A wide-angle perception lens, characterized in that: It includes a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens, and a seventh lens that are sequentially arranged along an optical axis from the object side to the image side. Each of the first lens to the seventh lens includes an object side facing the object side and allowing imaging light to pass through, and an image side facing the image side and allowing imaging light to pass through. The lenses in the wide-angle perception lens are only composed of seven lenses; The first lens has a negative refractive power, and the object side of the first lens is convex, and the image side is concave; The second lens has a negative refractive power, and the object side of the second lens is concave, and the image side is convex; The third lens has a positive refractive power, and the object side of the third lens is convex, and the image side is convex; The fourth lens has a positive refractive power, and the object side of the fourth lens is convex, and the image side is convex; The fifth lens has a positive refractive power, and the object side of the fifth lens is convex, and the image side is convex; The sixth lens has a negative refractive power, and the object side of the sixth lens is concave, and the image side is concave; The seventh lens has a positive refractive power, and the object side of the seventh lens is convex, and the image side is convex; Among them, the second lens, the fourth lens, and the seventh lens are all aspherical lenses. The second lens satisfies: 0.05 ≤ (G21 / D2) ≤ 0.3, where G21 is the sagitta height of the second lens, and D2 is the outer diameter of the second lens; This lens satisfies: TTL / h ≤ 3.7, where TTL is the total optical length of the lens, and h is the designed image height of the optical lens; This lens satisfies: BFL / TTL > 0.12, where BFL is the back focal length of the lens, and TTL is the total optical length of the lens.

2. The wide-angle sensing lens as described in claim 1, characterized in that: The first lens satisfies: nd1 > 1.8, where nd1 is the refractive index of the first lens.

3. A wide-angle sensing lens as described in claim 1, characterized in that: The fourth lens is a positive lens, and when the ambient temperature is -40°C to 105°C, its refractive index temperature coefficient dn / dT satisfies: dn / dT < -2*10E-6.

4. A wide-angle sensing lens as described in claim 1, characterized in that: The fourth lens satisfies: 0.7 < T4 / BFL < 1.2, where T4 is the central thickness of the fourth lens, and BFL is the back focal length of the lens optical.

5. A wide-angle sensing lens as described in claim 1, characterized in that: The fourth lens satisfies: 2.0 < f4 / f < 3.0, where f4 is the focal length of the fourth lens, and f is the system focal length.

6. A wide-angle sensing lens as described in claim 1, characterized in that: The image side of the fifth lens and the object side of the sixth lens are glued together, and the refractive index temperature coefficient Dn / dt of the fifth lens is negative, and the refractive index temperature coefficient Dn / dt of the sixth lens is positive.

7. A wide-angle sensing lens as described in claim 1, characterized in that: The image side of the fifth lens and the object side of the sixth lens are glued together, and satisfy: |Vd6 - Vd5| > 30, where Vd5 is the dispersion coefficient of the fifth lens, and Vd6 is the dispersion coefficient of the sixth lens.

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