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CN-118707686-B - Optical lens

CN118707686BCN 118707686 BCN118707686 BCN 118707686BCN-118707686-B

Abstract

The invention provides an optical lens which comprises eight lenses in sequence from an object side to an imaging surface along an optical axis, wherein the first lens is provided with negative focal power, the image side surface is a concave surface, the second lens is provided with negative focal power, the object side surface is a convex surface, the image side surface is a concave surface, the third lens is provided with positive focal power, the object side surface is a concave surface, the image side surface is a convex surface, the fourth lens is provided with positive focal power, the object side surface is a concave surface, the image side surface is a convex surface, the fifth lens is provided with positive focal power, the object side surface is a concave surface, the image side surface is a convex surface, the sixth lens is provided with negative focal power, the object side surface is a concave surface, the seventh lens is provided with positive focal power, and the eighth lens is provided with negative focal power. The optical lens provided by the invention improves the imaging quality of the optical lens, reduces the aberration and improves the imaging quality of the optical lens through reasonable configuration of the surface types of the lenses and reasonable collocation of the focal power.

Inventors

  • Li Zhaochenxi
  • WEI WENZHE
  • WANG KEMIN

Assignees

  • 江西联创电子有限公司

Dates

Publication Date
20260512
Application Date
20240620

Claims (10)

  1. 1. An optical lens comprising eight lenses in total, in order from an object side to an imaging plane along an optical axis: A first lens having negative optical power, the image side surface of which is concave; a second lens element with negative refractive power having a convex object-side surface and a concave image-side surface; The object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; A fifth lens element with positive refractive power having a concave object-side surface and a convex image-side surface; a sixth lens with negative focal power, the object side surface of which is a concave surface; a seventh lens having positive optical power, an image side surface of which is convex; an eighth lens having negative optical power; The effective focal length f of the optical lens and the object side surface curvature radius R9 of the fifth lens meet the condition that R9/f < -1; The maximum field angle FOV of the optical lens and the aperture value FNo of the optical lens meet the conditions that the FOV/FNo is 50 degrees <65 degrees; The maximum field angle FOV of the optical lens, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens meet 31 DEG < FOV multiplied by f/IH <45 deg.
  2. 2. The optical lens of claim 1, wherein an effective focal length f of the optical lens and an object side curvature radius R9 of the fifth lens satisfy-7978185.02 < R9/f < -1 >, a maximum field angle FOV of the optical lens and an aperture value FNo of the optical lens satisfy 56 ° < FOV/FNo <60 °, and a real image height IH corresponding to the maximum field angle FOV of the optical lens, the effective focal length f of the optical lens and the maximum field angle of the optical lens satisfy 36 ° < FOV x f/IH <41 °.
  3. 3. The optical lens according to claim 1, wherein an effective focal length f of the optical lens and a back focal length BFL of the optical lens satisfy 0.8< BFL/f <1.1.
  4. 4. The optical lens of claim 1, wherein an effective focal length f of the optical lens and an object-side curvature radius R7 of the fourth lens satisfy-90.45≤R7/f < -5.5, and an effective focal length f of the optical lens and an image-side curvature radius R8 of the fourth lens satisfy-2.3 < R8/f < -1.2.
  5. 5. The optical lens of claim 1, wherein the effective focal length f of the optical lens and the image side radius of curvature R10 of the fifth lens satisfy-1.5 < R10/f < -0.5.
  6. 6. The optical lens of claim 1, wherein the object-side radius of curvature R9 of the fifth lens and the image-side radius of curvature R10 of the fifth lens satisfy R9/R10>1.
  7. 7. The optical lens of claim 1, wherein a focal length f4 of the fourth lens and an object-side curvature radius R7 of the fourth lens satisfy-31 < R7/f4< -1.5, and a focal length f4 of the fourth lens and an image-side curvature radius R8 of the fourth lens satisfy-0.7 < R8/f4< -0.3.
  8. 8. The optical lens of claim 1, wherein a focal length f5 of the fifth lens and an object-side radius of curvature R9 of the fifth lens satisfy R9/f5< -1.
  9. 9. The optical lens of claim 1, wherein the object-side radius of curvature R7 of the fourth lens and the object-side radius of curvature R9 of the fifth lens satisfy-1 < (R7-R9)/(R7 + R9) <0.
  10. 10. The optical lens of claim 1, wherein the object-side light-transmitting half-caliber sagittal height Sag9 of the fifth lens satisfies 0< Sag9<0.05mm, the object-side curvature radius R9 of the fifth lens and the image-side curvature radius R10 of the fifth lens satisfy 1< R9/R10 < 9224404.39, and the focal length f5 of the fifth lens and the object-side curvature radius R9 of the fifth lens satisfy-4593791.27 < R9/f5< -1.

Description

Optical lens Technical Field The invention relates to the technical field of imaging lenses, in particular to an optical lens. Background With the continuous progress and development of the existing image processing algorithm and AI technology, the optical lens is widely applied to various fields such as a motion camera, a vehicle-mounted lens, an intelligent home and the like. However, the optical lens of the existing moving camera has various defects in underwater imaging, such as degradation of imaging quality, poor light transmission performance, incapability of adapting to darker environments, and small imaging target surface of the existing lens, and is difficult to meet market demands. Accordingly, there is a need to develop an optical lens having one or more of the advantages of ultra-wide angle, high imaging quality, high pixels, etc., to better meet the high demands of the market for underwater lenses. Disclosure of Invention In view of the foregoing, it is an object of the present invention to provide an optical lens having one or more advantages of ultra-wide angle, high pixel, high imaging quality, and the like. The invention provides an optical lens, which comprises eight lenses in sequence from an object side to an imaging surface along an optical axis: A first lens having negative optical power, the image side surface of which is concave; a second lens element with negative refractive power having a convex object-side surface and a concave image-side surface; The object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; A fifth lens element with positive refractive power having a concave object-side surface and a convex image-side surface; a sixth lens with negative focal power, the object side surface of which is a concave surface; a seventh lens having positive optical power, an image side surface of which is convex; an eighth lens having negative optical power; the effective focal length f of the optical lens and the object side surface curvature radius R9 of the fifth lens meet the requirement that R9/f < -1. Further preferably, the maximum field angle FOV of the optical lens and the aperture value FNo of the optical lens satisfy 50 DEG < FOV/FNo <65 deg. Further preferably, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy BFL/f >0.8. Further preferably, the effective focal length f of the optical lens and the object side curvature radius R7 of the fourth lens meet R7/f < -5.5, and the effective focal length f of the optical lens and the image side curvature radius R8 of the fourth lens meet-2.3 < R8/f < -1.2. Further preferably, the effective focal length f of the optical lens and the image side curvature radius R10 of the fifth lens satisfy-1.5 < R10/f < -0.5. Further preferably, the object-side radius of curvature R9 of the fifth lens and the image-side radius of curvature R10 of the fifth lens satisfy R9/R10>1. Further preferably, the focal length f4 of the fourth lens and the object-side curvature radius R7 of the fourth lens satisfy R7/f4< -1.2, and the focal length f4 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy-0.7 < R8/f4< -0.3. Further preferably, the focal length f5 of the fifth lens and the object-side surface radius of curvature R9 of the fifth lens satisfy R9/f5< -1. Further preferably, the object-side radius of curvature R7 of the fourth lens and the object-side radius of curvature R9 of the fifth lens satisfy-1 < (R7-R9)/(R7 + R9) <0. Further preferably, the object side light-transmitting half-caliber sagittal height Sag9 of the fifth lens is 0< Sag9<0.05mm. The optical lens provided by the invention improves the imaging quality of the optical lens, reduces the aberration and improves the imaging quality of the optical lens through reasonable configuration of the surface types of the lenses and reasonable collocation of the focal power, so that the lens has one or more advantages of ultra-wide angle, high pixels, high imaging quality and the like. Drawings The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which: fig. 1 is a schematic structural diagram of an optical lens in embodiment 1 of the present invention. Fig. 2 is a graph showing a field curvature of an optical lens in embodiment 1 of the present invention. FIG. 3 is a graph showing F-theta distortion of an optical lens according to example 1 of the present invention. Fig. 4 is a graph showing a vertical axis chromatic aberration of an optical lens in embodiment 1 of the present invention. Fig. 5 is an axial aberration diagram of the optical lens in em