Search

CN-120370509-B - Optical lens

CN120370509BCN 120370509 BCN120370509 BCN 120370509BCN-120370509-B

Abstract

The invention provides an optical lens which comprises 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 negative focal power, a convex object side, a concave image side and a sixth lens with positive focal power, wherein the object side curvature radius R7 of the fourth lens and the image side curvature radius R8 of the fourth lens meet the condition that (R7-R8)/(R7+R 8) is less than-0.45. The optical lens provided by the invention has one or more advantages of large target surface, large aperture, small distortion and the like.

Inventors

  • Xiao Pulu
  • Li Zhaochenxi
  • LING BINGBING

Assignees

  • 江西联创电子有限公司

Dates

Publication Date
20260512
Application Date
20250427

Claims (10)

  1. 1. An optical lens comprising six lenses in order from an object side to an imaging surface along an optical axis, comprising: a first lens having negative optical power; A second lens element with negative refractive power having a concave object-side surface at a paraxial region and a concave image-side surface; a third lens having positive optical power, the object side surface of which is a convex surface; A fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface; a fifth lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a sixth lens having positive optical power; Wherein the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy-0.8 < (R7-R8)/(R7 + R8) < -0.45; The total optical length TTL of the optical lens and the effective focal length f of the optical lens meet 4.5< TTL/f <5.2, and the real image height IH corresponding to the maximum field angle of the optical lens and the total optical length TTL of the optical lens meet 4< TTL/IH <4.8; The focal length f2 of the second lens and the effective focal length f of the optical lens meet the conditions that-3.6 < f2/f < -1.5; The focal length f1 of the first lens and the effective focal length f of the optical lens meet the condition that-7.8 < f1/f < -3.1.
  2. 2. 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 meet 4.51< TTL/f <5.19, and the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens meet 4.03< TTL/IH <4.75; The focal length f2 of the second lens and the effective focal length f of the optical lens meet the conditions that-3.56 < f2/f < -1.55; the focal length f1 of the first lens and the effective focal length f of the optical lens meet the condition that 7.72< f1/f < -3.13.
  3. 3. The optical lens according to claim 1, wherein the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy 38 ° < FOV/Fno <42 °, and the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy 1.6< IH/EPD <1.8.
  4. 4. The optical lens according to claim 1, wherein a real image height IH corresponding to a maximum field angle of the optical lens and an effective focal length f of the optical lens satisfy 1< IH/f <1.2, and a back focal length BFL of the optical lens and an effective focal length f of the optical lens satisfy 1< BFL/f <1.4.
  5. 5. The optical lens system according to claim 1, wherein a total image height IH corresponding to a maximum angle of view of the optical lens and a maximum angle of view FOV of the optical lens are 2.3< d 1/(IH/2)/tan (FOV/2) <2.9, and a combined focal length f123 of the first lens, the second lens and the third lens and a combined focal length f456 of the fourth lens, the fifth lens and the sixth lens are 0.9< f123/f456<134.
  6. 6. The optical lens of claim 1, wherein the object-side radius of curvature R3 of the second lens and the effective focal length f of the optical lens satisfy-6.9 < R3/f < -1, and wherein the image-side radius of curvature R4 of the second lens and the effective focal length f of the optical lens satisfy 1< R4/f <7.4.
  7. 7. The optical lens of claim 1, wherein a focal length f4 of the fourth lens and an effective focal length f of the optical lens satisfy 1.2< f4/f <2.4, an object-side radius of curvature R7 of the fourth lens and an effective focal length f of the optical lens satisfy 0.9< R7/f <1.2, and an image-side radius of curvature R8 of the fourth lens and an effective focal length f of the optical lens satisfy 3.1< R8/f <8.1.
  8. 8. The optical lens of claim 1, wherein a focal length f5 of the fifth lens and an effective focal length f of the optical lens satisfy-1.9 < f5/f < -1.1, and an object-side radius of curvature R9 of the fifth lens and an image-side radius of curvature R10 of the fifth lens satisfy 0.47< (R9-R10)/(R9+R10) <0.79.
  9. 9. The optical lens of claim 1, wherein a focal length f6 of the sixth lens and an effective focal length f of the optical lens satisfy 1.4< f6/f <5.2, and an object-side radius of curvature R11 of the sixth lens and an image-side radius of curvature R12 of the sixth lens satisfy 0.04< R11/R12<3.41.
  10. 10. The optical lens of claim 1, wherein an object-side light-transmitting half-caliber sagittal height Sag7 of the fourth lens and an object-side light-transmitting half-caliber d7 of the fourth lens satisfy 0.28< Sag7/d7<0.44, and an image-side light-transmitting half-caliber sagittal height Sag8 of the fourth lens and an image-side light-transmitting half-caliber d8 of the fourth lens satisfy 0.03< Sag8/d8<0.1.

Description

Optical lens Technical Field The invention relates to the technical field of imaging lenses, in particular to an optical lens. Background At the moment of the vigorous development of automobile auxiliary driving and automatic driving technologies, the vehicle-mounted camera has a very important position. The vehicle-mounted cameras are various in types, including inward vision, backward vision, forward vision, side vision, circular vision and the like. The functions of the two components are unique, and the two components have different application scenes. For example, the forward-looking wide-angle camera is mainly used for accurately identifying a close-range object, and can provide key information for driving in the scenes of urban road working conditions, low-speed running of vehicles and the like. And the front view camera is called as a core component of an ADAS (advanced driving assistance system). The method not only carries the heavy duty of ranging, but also can accurately identify objects and clearly distinguish road marks, and as a result, the required visual algorithm is extremely complex and the technical threshold is quite high. In order to fully exert the performance of the front-view camera, it is urgent to develop an optical lens with excellent imaging effect, and only then can ensure stable and efficient operation in a complex driving environment, thus building a firm foundation for further development of automatic driving technology. Disclosure of Invention In view of the foregoing, an object of the present invention is to provide an optical lens having an advantage of excellent imaging quality. The invention adopts the technical scheme that: An optical lens comprising six lenses in order from an object side to an imaging surface along an optical axis: a first lens having negative optical power; A second lens element with negative refractive power having a concave object-side surface at a paraxial region and a concave image-side surface; a third lens having positive optical power, the object side surface of which is a convex surface; A fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface; a fifth lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a sixth lens having positive optical power; wherein the object-side surface curvature radius R7 of the fourth lens and the image-side surface curvature radius R8 of the fourth lens satisfy-0.8 < (R7-R8)/(R7 + R8) < -0.45. Further preferably, the optical total length TTL of the optical lens and the effective focal length f of the optical lens meet 4.5< TTL/f <5.2, and the real image height IH corresponding to the maximum field angle of the optical lens and the optical total length TTL of the optical lens meet 4< TTL/IH <4.8. Further preferably, the maximum field angle FOV of the optical lens and the aperture value FNo of the optical lens satisfy 38 DEG < FOV/FNo <42 DEG, and the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy 1.6< IH/EPD <1.8. Further preferably, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens meet 1< IH/f <1.2, and the back focal length BFL of the optical lens and the effective focal length f of the optical lens meet 1< BFL/f <1.4. Further preferably, the light passing half aperture d1 of the object side surface of the first lens, the real image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy 2.3< d 1/(IH/2)/tan (FOV/2) <2.9, and the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f456 of the fourth lens, the fifth lens and the sixth lens satisfy 0.9< f123/f456<134. Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens meet-3.6 < f2/f < -1.5, the object-side surface curvature radius R3 of the second lens and the effective focal length f of the optical lens meet-6.9 < R3/f < -1, and the image-side surface curvature radius R4 of the second lens and the effective focal length f of the optical lens meet-1 < R4/f <7.4. Further preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens meet 1.2< f4/f <2.4, the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens meet 0.9< R7/f <1.2, and the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens meet 3.1< R8/f <8.1. Further preferably, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy-1.9 < f5/f < -1.1, and the object-side curvature radius R9 of the fifth lens and the image-side curv